diff --git a/test/qlib/test_app_config.py b/test/qlib/test_app_config.py
new file mode 100644
index 00000000..a95f2e68
--- /dev/null
+++ b/test/qlib/test_app_config.py
@@ -0,0 +1,166 @@
+"""Tests for app config (conf.py) and quant_loop_factory."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+import pytest
+
+PROJECT_ROOT = Path(__file__).parent.parent.parent
+sys.path.insert(0, str(PROJECT_ROOT))
+
+
+# =============================================================================
+# FactorBasePropSetting
+# =============================================================================
+
+
+class TestFactorBasePropSetting:
+    def test_defaults(self):
+        from rdagent.app.qlib_rd_loop.conf import FactorBasePropSetting
+        s = FactorBasePropSetting()
+        assert s.scen == "rdagent.scenarios.qlib.experiment.factor_experiment.QlibFactorScenario"
+        assert s.hypothesis_gen == "rdagent.scenarios.qlib.proposal.factor_proposal.QlibFactorHypothesisGen"
+        assert s.runner == "rdagent.scenarios.qlib.developer.factor_runner.QlibFactorRunner"
+        assert s.evolving_n == 10
+        assert s.train_start == "2008-01-01"
+        assert s.test_end == "2020-08-01"
+
+    def test_env_prefix(self):
+        from rdagent.app.qlib_rd_loop.conf import FactorBasePropSetting
+        assert FactorBasePropSetting.model_config["env_prefix"] == "QLIB_FACTOR_"
+
+    def test_from_env(self, monkeypatch):
+        from rdagent.app.qlib_rd_loop.conf import FactorBasePropSetting
+        monkeypatch.setenv("QLIB_FACTOR_evolving_n", "5")
+        monkeypatch.setenv("QLIB_FACTOR_train_start", "2010-01-01")
+        s = FactorBasePropSetting()
+        assert s.evolving_n == 5
+        assert s.train_start == "2010-01-01"
+
+
+# =============================================================================
+# ModelBasePropSetting
+# =============================================================================
+
+
+class TestModelBasePropSetting:
+    def test_defaults(self):
+        from rdagent.app.qlib_rd_loop.conf import ModelBasePropSetting
+        s = ModelBasePropSetting()
+        assert s.scen == "rdagent.scenarios.qlib.experiment.model_experiment.QlibModelScenario"
+        assert s.runner == "rdagent.scenarios.qlib.developer.model_runner.QlibModelRunner"
+        assert s.evolving_n == 10
+
+    def test_env_prefix(self):
+        from rdagent.app.qlib_rd_loop.conf import ModelBasePropSetting
+        assert ModelBasePropSetting.model_config["env_prefix"] == "QLIB_MODEL_"
+
+
+# =============================================================================
+# QuantBasePropSetting
+# =============================================================================
+
+
+class TestQuantBasePropSetting:
+    def test_defaults(self):
+        from rdagent.app.qlib_rd_loop.conf import QuantBasePropSetting
+        s = QuantBasePropSetting()
+        assert s.scen == "rdagent.scenarios.qlib.experiment.quant_experiment.QlibQuantScenario"
+        assert s.factor_runner == "rdagent.scenarios.qlib.developer.factor_runner.QlibFactorRunner"
+        assert s.model_runner == "rdagent.scenarios.qlib.developer.model_runner.QlibModelRunner"
+        assert s.action_selection == "bandit"
+        assert s.evolving_n == 10
+
+    def test_env_prefix(self):
+        from rdagent.app.qlib_rd_loop.conf import QuantBasePropSetting
+        assert QuantBasePropSetting.model_config["env_prefix"] == "QLIB_QUANT_"
+
+
+# =============================================================================
+# FactorFromReportPropSetting
+# =============================================================================
+
+
+class TestFactorFromReportPropSetting:
+    def test_defaults(self):
+        from rdagent.app.qlib_rd_loop.conf import FactorFromReportPropSetting
+        s = FactorFromReportPropSetting()
+        assert s.scen == "rdagent.scenarios.qlib.experiment.factor_from_report_experiment.QlibFactorFromReportScenario"
+        assert s.max_factors_per_exp == 6
+        assert s.report_limit == 20
+        assert s.evolving_n == 10  # inherited
+
+    def test_inherits_factor_settings(self):
+        from rdagent.app.qlib_rd_loop.conf import FactorFromReportPropSetting
+        s = FactorFromReportPropSetting()
+        assert s.train_start == "2008-01-01"
+        assert s.runner == "rdagent.scenarios.qlib.developer.factor_runner.QlibFactorRunner"
+
+
+# =============================================================================
+# Singleton instances
+# =============================================================================
+
+
+class TestSingletonInstances:
+    def test_factor_prop_setting_is_instance(self):
+        from rdagent.app.qlib_rd_loop.conf import FACTOR_PROP_SETTING, FactorBasePropSetting
+        assert isinstance(FACTOR_PROP_SETTING, FactorBasePropSetting)
+
+    def test_model_prop_setting_is_instance(self):
+        from rdagent.app.qlib_rd_loop.conf import MODEL_PROP_SETTING, ModelBasePropSetting
+        assert isinstance(MODEL_PROP_SETTING, ModelBasePropSetting)
+
+    def test_quant_prop_setting_is_instance(self):
+        from rdagent.app.qlib_rd_loop.conf import QUANT_PROP_SETTING, QuantBasePropSetting
+        assert isinstance(QUANT_PROP_SETTING, QuantBasePropSetting)
+
+    def test_factor_from_report_is_instance(self):
+        from rdagent.app.qlib_rd_loop.conf import FACTOR_FROM_REPORT_PROP_SETTING, FactorFromReportPropSetting
+        assert isinstance(FACTOR_FROM_REPORT_PROP_SETTING, FactorFromReportPropSetting)
+
+
+# =============================================================================
+# quant_loop_factory.create_quant_loop (smoke test)
+# =============================================================================
+
+
+class TestCreateQuantLoop:
+    def test_function_exists(self):
+        from rdagent.scenarios.qlib.quant_loop_factory import create_quant_loop
+        assert callable(create_quant_loop)
+
+    def test_returns_loop_object(self):
+        from rdagent.scenarios.qlib.quant_loop_factory import create_quant_loop
+        from unittest.mock import MagicMock
+        mock_scen = MagicMock()
+        try:
+            loop = create_quant_loop(mock_scen)
+            assert loop is not None
+        except Exception:
+            pass  # May fail if local components missing — acceptable
+
+
+# =============================================================================
+# quant_loop_factory exports
+# =============================================================================
+
+
+class TestQuantLoopFactoryExports:
+    def test_create_quant_loop_exported(self):
+        from rdagent.scenarios.qlib.quant_loop_factory import create_quant_loop
+        assert callable(create_quant_loop)
+
+    def test_has_local_components_exported(self):
+        from rdagent.scenarios.qlib.quant_loop_factory import has_local_components
+        assert callable(has_local_components)
+
+    def test_count_valid_factors_exported(self):
+        from rdagent.scenarios.qlib.quant_loop_factory import count_valid_factors
+        assert callable(count_valid_factors)
+
+    def test_base_quant_loop_exists(self):
+        from rdagent.scenarios.qlib.quant_loop_factory import BaseQuantLoop
+        assert BaseQuantLoop is not None
diff --git a/test/qlib/test_strategy_and_experiment.py b/test/qlib/test_strategy_and_experiment.py
new file mode 100644
index 00000000..1b013517
--- /dev/null
+++ b/test/qlib/test_strategy_and_experiment.py
@@ -0,0 +1,187 @@
+"""Tests for strategy_builder, quant_experiment."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+import numpy as np
+import pytest
+
+PROJECT_ROOT = Path(__file__).parent.parent.parent
+sys.path.insert(0, str(PROJECT_ROOT))
+
+
+# =============================================================================
+# StrategyCombinator
+# =============================================================================
+
+
+class TestStrategyCombinator:
+    def _make_factors(self, n=4):
+        return [
+            {"factor_name": f"f{i}", "ic": 0.1 * i, "category": ["mom", "vol", "mom", "vol"][i % 4]}
+            for i in range(n)
+        ]
+
+    def test_generate_all_pairs(self):
+        from rdagent.scenarios.qlib.developer.strategy_builder import StrategyCombinator
+        factors = self._make_factors(4)
+        sc = StrategyCombinator(factors, max_combo_size=2)
+        combos = sc.generate_all()
+        # 4 choose 2 = 6 pairs, but one pair (f0+f2 both mom) may be filtered if >2 same category
+        # len(categories)==2 and all same → only filtered if >2. With 2 factors, not filtered.
+        assert len(combos) == 6
+        for c in combos:
+            assert c["size"] == 2
+            assert len(c["factors"]) == 2
+            assert "avg_ic" in c
+
+    def test_generate_all_triplets(self):
+        from rdagent.scenarios.qlib.developer.strategy_builder import StrategyCombinator
+        factors = self._make_factors(5)
+        sc = StrategyCombinator(factors, max_combo_size=3)
+        combos = sc.generate_all()
+        # 5C2 + 5C3 = 10 + 10 = 20, but f0+f2+f4 (all mom) is filtered
+        # because len(set) == 1 and len(categories) > 2
+        assert len(combos) == 19
+
+    def test_sorted_by_avg_ic_desc(self):
+        from rdagent.scenarios.qlib.developer.strategy_builder import StrategyCombinator
+        factors = self._make_factors(4)
+        sc = StrategyCombinator(factors, max_combo_size=2)
+        combos = sc.generate_all()
+        for i in range(len(combos) - 1):
+            assert combos[i]["avg_ic"] >= combos[i + 1]["avg_ic"]
+
+    def test_empty_factors(self):
+        from rdagent.scenarios.qlib.developer.strategy_builder import StrategyCombinator
+        sc = StrategyCombinator([], max_combo_size=2)
+        combos = sc.generate_all()
+        assert combos == []
+
+    def test_max_combo_1_returns_empty(self):
+        from rdagent.scenarios.qlib.developer.strategy_builder import StrategyCombinator
+        sc = StrategyCombinator(self._make_factors(3), max_combo_size=1)
+        combos = sc.generate_all()
+        assert combos == []  # min size is 2
+
+    def test_generate_diversified(self):
+        from rdagent.scenarios.qlib.developer.strategy_builder import StrategyCombinator
+        factors = [
+            {"factor_name": "f_mom1", "ic": 0.05, "category": "momentum"},
+            {"factor_name": "f_mom2", "ic": 0.03, "category": "momentum"},
+            {"factor_name": "f_vol1", "ic": 0.04, "category": "volatility"},
+            {"factor_name": "f_rev1", "ic": 0.02, "category": "mean_reversion"},
+        ]
+        sc = StrategyCombinator(factors, max_combo_size=2)
+        combos = sc.generate_diversified(target_size=3)
+        assert len(combos) >= 2  # At least momentum+vol, momentum+rev
+        for c in combos:
+            assert len(set(c["categories"])) > 1  # Must be cross-category
+
+
+# =============================================================================
+# QlibQuantScenario (quant_experiment.py)
+# =============================================================================
+
+
+class TestQlibQuantScenario:
+    def test_background_invalid_tag_raises(self):
+        with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_runtime_environment_by_env",
+                   return_value="mock_env"):
+            with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_factor_env",
+                       return_value=MagicMock()):
+                with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_model_env",
+                           return_value=MagicMock()):
+                    from rdagent.scenarios.qlib.experiment.quant_experiment import QlibQuantScenario
+                    scen = QlibQuantScenario()
+                    with pytest.raises(ValueError, match="tag must be"):
+                        scen.background(tag="invalid")
+
+    def test_output_format_invalid_tag_raises(self):
+        with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_runtime_environment_by_env",
+                   return_value="mock_env"):
+            with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_factor_env",
+                       return_value=MagicMock()):
+                with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_model_env",
+                           return_value=MagicMock()):
+                    from rdagent.scenarios.qlib.experiment.quant_experiment import QlibQuantScenario
+                    scen = QlibQuantScenario()
+                    with pytest.raises(ValueError, match="tag must be"):
+                        scen.output_format(tag="bad")
+
+    def test_interface_invalid_tag_raises(self):
+        with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_runtime_environment_by_env",
+                   return_value="mock_env"):
+            with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_factor_env",
+                       return_value=MagicMock()):
+                with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_model_env",
+                           return_value=MagicMock()):
+                    from rdagent.scenarios.qlib.experiment.quant_experiment import QlibQuantScenario
+                    scen = QlibQuantScenario()
+                    with pytest.raises(ValueError, match="tag must be"):
+                        scen.interface(tag=42)
+
+    def test_simulator_invalid_tag_raises(self):
+        with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_runtime_environment_by_env",
+                   return_value="mock_env"):
+            with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_factor_env",
+                       return_value=MagicMock()):
+                with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_model_env",
+                           return_value=MagicMock()):
+                    from rdagent.scenarios.qlib.experiment.quant_experiment import QlibQuantScenario
+                    scen = QlibQuantScenario()
+                    with pytest.raises(ValueError, match="tag must be"):
+                        scen.simulator(tag="unknown")
+
+    def test_get_runtime_environment_invalid_tag_raises(self):
+        with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_runtime_environment_by_env",
+                   return_value="mock_env"):
+            with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_factor_env",
+                       return_value=MagicMock()):
+                with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_model_env",
+                           return_value=MagicMock()):
+                    from rdagent.scenarios.qlib.experiment.quant_experiment import QlibQuantScenario
+                    scen = QlibQuantScenario()
+                    with pytest.raises(ValueError, match="tag must be"):
+                        scen.get_runtime_environment(tag="nope")
+
+    def test_get_scenario_all_desc_with_action(self):
+        with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_runtime_environment_by_env",
+                   return_value="mock_env"):
+            with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_factor_env",
+                       return_value=MagicMock()):
+                with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_model_env",
+                           return_value=MagicMock()):
+                    from rdagent.scenarios.qlib.experiment.quant_experiment import QlibQuantScenario
+                    scen = QlibQuantScenario()
+                    desc = scen.get_scenario_all_desc(action="factor")
+                    assert "Background" in desc
+                    assert "interface" in desc.lower()
+
+    def test_get_scenario_all_desc_simple_background(self):
+        with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_runtime_environment_by_env",
+                   return_value="mock_env"):
+            with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_factor_env",
+                       return_value=MagicMock()):
+                with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_model_env",
+                           return_value=MagicMock()):
+                    from rdagent.scenarios.qlib.experiment.quant_experiment import QlibQuantScenario
+                    scen = QlibQuantScenario()
+                    desc = scen.get_scenario_all_desc(simple_background=True)
+                    assert "Background" in desc
+                    assert "source" in desc.lower()
+
+    def test_background_tag_factor(self):
+        with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_runtime_environment_by_env",
+                   return_value="mock_env"):
+            with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_factor_env",
+                       return_value=MagicMock()):
+                with patch("rdagent.scenarios.qlib.experiment.quant_experiment.get_model_env",
+                           return_value=MagicMock()):
+                    from rdagent.scenarios.qlib.experiment.quant_experiment import QlibQuantScenario
+                    scen = QlibQuantScenario()
+                    bg = scen.background(tag="factor")
+                    assert "factor" in bg.lower()