diff --git a/MtApi5/Events/Mt5EventTypes.cs b/MtApi5/Events/Mt5EventTypes.cs
index 2201a791..6fb3a3bd 100644
--- a/MtApi5/Events/Mt5EventTypes.cs
+++ b/MtApi5/Events/Mt5EventTypes.cs
@@ -2,6 +2,7 @@
 {
     internal enum Mt5EventTypes
     {
-        OnTradeTransaction = 1
+        OnTradeTransaction = 1,
+        OnBookEvent        = 2
     }
 }
diff --git a/MtApi5/Events/OnBookEvent.cs b/MtApi5/Events/OnBookEvent.cs
new file mode 100644
index 00000000..d3f57811
--- /dev/null
+++ b/MtApi5/Events/OnBookEvent.cs
@@ -0,0 +1,7 @@
+namespace MtApi5.Events
+{
+    internal class OnBookEvent
+    {
+        public string Symbol { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/MtApi5/Mt5BookEventArgs.cs b/MtApi5/Mt5BookEventArgs.cs
new file mode 100644
index 00000000..6a280cb5
--- /dev/null
+++ b/MtApi5/Mt5BookEventArgs.cs
@@ -0,0 +1,10 @@
+using System;
+
+namespace MtApi5
+{
+    public class Mt5BookEventArgs : EventArgs
+    {
+        public int ExpertHandle { get; set; }
+        public string Symbol { get; set; }      //Symbol of OnBookEvent event.
+    }
+}
\ No newline at end of file
diff --git a/MtApi5/MtApi5.csproj b/MtApi5/MtApi5.csproj
index 4507f832..58dfa757 100755
--- a/MtApi5/MtApi5.csproj
+++ b/MtApi5/MtApi5.csproj
@@ -48,6 +48,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="CopyTicksFlag.cs" />
+    <Compile Include="Events\OnBookEvent.cs" />
     <Compile Include="Events\OnTradeTransactionEvent.cs" />
     <Compile Include="MqlBookInfo.cs" />
     <Compile Include="MqlParam.cs" />
@@ -55,6 +56,7 @@
     <Compile Include="MqlTick.cs" />
     <Compile Include="MqlTradeCheckResult.cs" />
     <Compile Include="MqlTradeTransaction.cs" />
+    <Compile Include="Mt5BookEventArgs.cs" />
     <Compile Include="Mt5TimeConverter.cs" />
     <Compile Include="Mt5Enums.cs" />
     <Compile Include="Mt5ConnectionEventArgs.cs" />
diff --git a/MtApi5/MtApi5Client.cs b/MtApi5/MtApi5Client.cs
index 393230e9..7c24ee34 100755
--- a/MtApi5/MtApi5Client.cs
+++ b/MtApi5/MtApi5Client.cs
@@ -2387,6 +2387,7 @@ namespace MtApi5
         public event EventHandler<Mt5QuoteEventArgs> QuoteRemoved;
         public event EventHandler<Mt5ConnectionEventArgs> ConnectionStateChanged;
         public event EventHandler<Mt5TradeTransactionEventArgs> OnTradeTransaction;
+        public event EventHandler<Mt5BookEventArgs> OnBookEvent;
         #endregion
 
         #region Private Methods
@@ -2464,6 +2465,9 @@ namespace MtApi5
                 case Mt5EventTypes.OnTradeTransaction:
                     ReceivedOnTradeTransaction(e.ExpertHandle, e.Payload);
                     break;
+                case Mt5EventTypes.OnBookEvent:
+                    ReceivedOnBookEvent(e.ExpertHandle, e.Payload);
+                    break;
                 default:
                     throw new ArgumentOutOfRangeException();
             }
@@ -2481,6 +2485,16 @@ namespace MtApi5
             });
         }
 
+        private void ReceivedOnBookEvent(int expertHandler, string payload)
+        {
+            var e = JsonConvert.DeserializeObject<OnBookEvent>(payload);
+            OnBookEvent?.Invoke(this, new Mt5BookEventArgs
+            {
+                ExpertHandle = expertHandler,
+                Symbol = e.Symbol
+            });
+        }
+
         private void Connect(string host, int port)
         {
             var client = new MtClient(host, port);
diff --git a/TestClients/MtApi5TestClient/ViewModel.cs b/TestClients/MtApi5TestClient/ViewModel.cs
index cde86b92..31fe1dc1 100755
--- a/TestClients/MtApi5TestClient/ViewModel.cs
+++ b/TestClients/MtApi5TestClient/ViewModel.cs
@@ -175,6 +175,7 @@ namespace MtApi5TestClient
             _mtApiClient.QuoteRemoved += mMtApiClient_QuoteRemoved;
             _mtApiClient.QuoteUpdated += mMtApiClient_QuoteUpdated;
             _mtApiClient.OnTradeTransaction += mMtApiClient_OnTradeTransaction;
+            _mtApiClient.OnBookEvent += _mtApiClient_OnBookEvent;
 
             _quotesMap = new Dictionary<string, QuoteViewModel>();
 
@@ -1014,6 +1015,11 @@ namespace MtApi5TestClient
             AddLog($"OnTradeTransaction: ExpertHandle = {e.ExpertHandle}.{Environment.NewLine}Transaction = {e.Trans}.{Environment.NewLine}Request = {e.Request}.{Environment.NewLine}Result = {e.Result}.");
         }
 
+        private void _mtApiClient_OnBookEvent(object sender, Mt5BookEventArgs e)
+        {
+            AddLog($"OnBookEvent: ExpertHandle = {e.ExpertHandle}, Symbol = {e.Symbol}");
+        }
+
         private void AddQuote(Mt5Quote quote)
         {
             if (quote == null)
diff --git a/mq5/MtApi5.ex5 b/mq5/MtApi5.ex5
index d76d6e4c..2c956cbb 100755
Binary files a/mq5/MtApi5.ex5 and b/mq5/MtApi5.ex5 differ
diff --git a/mq5/MtApi5.mq5 b/mq5/MtApi5.mq5
index 48b14d51..71f7e987 100755
--- a/mq5/MtApi5.mq5
+++ b/mq5/MtApi5.mq5
@@ -41,7 +41,7 @@
    bool getBooleanValue(int expertHandle, int paramIndex, bool& res, string& err);
 #import
 
-#define __DEBUG_LOG__
+//#define __DEBUG_LOG__
 
 input int Port = 8228;
 
@@ -85,12 +85,23 @@ void  OnTradeTransaction(
    )
 {
 #ifdef __DEBUG_LOG__
-   Print("%s:", __FUNCTION__);
+   PrintFormat("%s:", __FUNCTION__);
 #endif 
    
-   OnTradeTransactionEvent* transEvent = new OnTradeTransactionEvent(trans, request, result);
-   SendMtEvent(ON_TRADE_TRANSACTION_EVENT, transEvent);
-   delete transEvent;
+   MtOnTradeTransactionEvent* trans_event = new MtOnTradeTransactionEvent(trans, request, result);
+   SendMtEvent(ON_TRADE_TRANSACTION_EVENT, trans_event);
+   delete trans_event;
+}
+
+void OnBookEvent(const string& symbol)
+{
+#ifdef __DEBUG_LOG__
+   PrintFormat("%s: %s", __FUNCTION__, symbol);
+#endif 
+
+   MtOnBookEvent * book_event = new MtOnBookEvent(symbol);
+   SendMtEvent(ON_BOOK_EVENT, book_event);
+   delete book_event;
 }
 
 int preinit()
@@ -6043,7 +6054,8 @@ string ExecuteRequest_IndicatorCreate(JSONObject *jo)
 
 enum MtEventTypes
 {
-   ON_TRADE_TRANSACTION_EVENT = 1
+   ON_TRADE_TRANSACTION_EVENT = 1,
+   ON_BOOK_EVENT              = 2
 };
 
 class MtEvent
@@ -6052,10 +6064,10 @@ public:
    virtual JSONObject* CreateJson() = 0;
 };
 
-class OnTradeTransactionEvent : public MtEvent
+class MtOnTradeTransactionEvent : public MtEvent
 {
 public:
-   OnTradeTransactionEvent(const MqlTradeTransaction& trans, const MqlTradeRequest& request, const MqlTradeResult& result)
+   MtOnTradeTransactionEvent(const MqlTradeTransaction& trans, const MqlTradeRequest& request, const MqlTradeResult& result)
    {
       _trans = trans;
       _request = request;
@@ -6077,6 +6089,25 @@ private:
    MqlTradeResult _result;
 };
 
+class MtOnBookEvent : public MtEvent
+{
+public:
+   MtOnBookEvent(const string& symbol)
+   {
+      _symbol = symbol;
+   }
+   
+   virtual JSONObject* CreateJson()
+   {
+      JSONObject *jo = new JSONObject();
+      jo.put("Symbol", new JSONString(_symbol));
+      return jo;
+   }
+   
+private:
+   string _symbol;
+};
+
 void SendMtEvent(MtEventTypes eventType, MtEvent* mtEvent)
 {
 #ifdef __DEBUG_LOG__