diff --git a/SqlServerTest/Program.cs b/SqlServerTest/Program.cs
index 114e595ba..c13d548c4 100644
--- a/SqlServerTest/Program.cs
+++ b/SqlServerTest/Program.cs
@@ -20,7 +20,7 @@ namespace OrmTest
             /***Unit Test***/
             //new Field(1).Init();
             //new Where(1).Init();
-            //new Method(1).Init();
+            new Method(1).Init();
             //new JoinQuery(1).Init();
             //new SingleQuery(1).Init();
             //new SelectQuery(1).Init();
@@ -34,15 +34,15 @@ namespace OrmTest
             new SqlSugarPerformance(100).Select();
 
             /***Demo***/
-            OrmTest.Demo.Query.Init();
-            OrmTest.Demo.Insert.Init();
-            OrmTest.Demo.Delete.Init();
-            OrmTest.Demo.Update.Init();
-            OrmTest.Demo.DbFirst.Init();
-            OrmTest.Demo.JoinSql.Init();
-            OrmTest.Demo.Filter.Init();
-            OrmTest.Demo.MaterSlave.Init();
-            OrmTest.Demo.ComplexModel.Init();
+            //OrmTest.Demo.Query.Init();
+            //OrmTest.Demo.Insert.Init();
+            //OrmTest.Demo.Delete.Init();
+            //OrmTest.Demo.Update.Init();
+            //OrmTest.Demo.DbFirst.Init();
+            //OrmTest.Demo.JoinSql.Init();
+            //OrmTest.Demo.Filter.Init();
+            //OrmTest.Demo.MaterSlave.Init();
+            //OrmTest.Demo.ComplexModel.Init();
         }
     }
 }
diff --git a/SqlServerTest/UnitTest/ExpressionTest/Method.cs b/SqlServerTest/UnitTest/ExpressionTest/Method.cs
index f20b6790b..70f1fbc99 100644
--- a/SqlServerTest/UnitTest/ExpressionTest/Method.cs
+++ b/SqlServerTest/UnitTest/ExpressionTest/Method.cs
@@ -21,6 +21,13 @@ namespace OrmTest.UnitTest
             base.Begin();
             for (int i = 0; i < base.Count; i++)
             {
+
+                //Native methods
+                ConvetToString();
+                ExtendToString();
+                ExtendSubstring();
+
+                //SqlFun methods
                 IIF();
                 IIF2();
                 #region StringIsNullOrEmpty
@@ -62,6 +69,31 @@ namespace OrmTest.UnitTest
             base.End("Method Test");
         }
 
+        private void ExtendToString()
+        {
+            Expression<Func<Student, bool>> exp = it => it.Id.ToString() == "a";
+            SqlServerExpressionContext expContext = new SqlServerExpressionContext();
+            expContext.Resolve(exp, ResolveExpressType.WhereSingle);
+            var value = expContext.Result.GetString();
+            var pars = expContext.Parameters;
+            base.Check(value, pars, "(CAST([Id] AS NVARCHAR(MAX)) = @Const0 )", new List<SugarParameter>() {
+                 new SugarParameter("@Const0","a")
+            }, "To_string error");
+        }
+
+        private void ConvetToString()
+        {
+            Expression<Func<Student, bool>> exp = it => Convert.ToString(it.Id) == "a";
+            SqlServerExpressionContext expContext = new SqlServerExpressionContext();
+            expContext.Resolve(exp, ResolveExpressType.WhereSingle);
+            var value = expContext.Result.GetString();
+            var pars = expContext.Parameters;
+            base.Check(value, pars, "(CAST([Id] AS NVARCHAR(MAX)) = @Const0 )", new List<SugarParameter>() {
+                 new SugarParameter("@Const0","a")
+            }, "To_string error");
+        }
+
+
         private void Length()
         {
             Expression<Func<Student, bool>> exp = it => SqlFunc.Length("aaaa") > 1;
@@ -99,6 +131,19 @@ namespace OrmTest.UnitTest
                 new SugarParameter("@MethodConst0","aaaa"),   new SugarParameter("@MethodConst1",0) ,   new SugarParameter("@MethodConst2",2),new SugarParameter("@Const3","a")
             }, "Substring error");
         }
+        private void ExtendSubstring()
+        {
+            var x2 = Guid.NewGuid();
+            Expression<Func<Student, bool>> exp = it =>"aaaa".Substring(0, 2)== "a";
+            SqlServerExpressionContext expContext = new SqlServerExpressionContext();
+            expContext.Resolve(exp, ResolveExpressType.WhereSingle);
+            var value = expContext.Result.GetString();
+            var pars = expContext.Parameters;
+            base.Check(value, pars, "(SUBSTRING(@MethodConst0,1 + @MethodConst1,@MethodConst2) = @Const3 )", new List<SugarParameter>() {
+                new SugarParameter("@MethodConst0","aaaa"),   new SugarParameter("@MethodConst1",0) ,   new SugarParameter("@MethodConst2",2),new SugarParameter("@Const3","a")
+            }, "Substring error");
+        }
+        
 
         private void ToBool()
         {
diff --git a/SqlSugar/ExpressionsToSql/ResolveItems/MethodCallExpressionResolve.cs b/SqlSugar/ExpressionsToSql/ResolveItems/MethodCallExpressionResolve.cs
index fd570f056..a7ac36044 100644
--- a/SqlSugar/ExpressionsToSql/ResolveItems/MethodCallExpressionResolve.cs
+++ b/SqlSugar/ExpressionsToSql/ResolveItems/MethodCallExpressionResolve.cs
@@ -1,6 +1,7 @@
 using SqlSugar;
 using System;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Linq;
 using System.Linq.Expressions;
 using System.Text;
@@ -12,10 +13,29 @@ namespace SqlSugar
         {
             var express = base.Expression as MethodCallExpression;
             var isLeft = parameter.IsLeft;
+            var isValidNativeMethod =
+                express.Method.Name.IsIn(
+                               "ToString", "ToInt32", "ToInt64", 
+                               "Length", "Replace", "Substring",
+                               "Contains", "EndsWith", "StartsWith",
+                               "HasValue", "Trim", "Equals",
+                               "ToLower", "ToUpper"); 
+            if (isValidNativeMethod)
+            {
+                NativeExtensionMethod(parameter, express, isLeft);
+            }
+            else
+            {
+                SqlFuncMethod(parameter, express, isLeft);
+            }
+        }
+
+        private void SqlFuncMethod(ExpressionParameter parameter, MethodCallExpression express, bool? isLeft)
+        {
             CheckMethod(express);
             var method = express.Method;
             string name = method.Name;
-            var args = express.Arguments;
+            var args = express.Arguments.Cast<Expression>().ToList();
             MethodCallExpressionModel model = new MethodCallExpressionModel();
             model.Args = new List<MethodCallExpressionArgs>();
             switch (this.Context.ResolveType)
@@ -35,7 +55,37 @@ namespace SqlSugar
                     break;
             }
         }
-        private void Select(ExpressionParameter parameter, bool? isLeft, string name, System.Collections.ObjectModel.ReadOnlyCollection<Expression> args, MethodCallExpressionModel model)
+
+        private void NativeExtensionMethod(ExpressionParameter parameter, MethodCallExpression express, bool? isLeft)
+        {
+            var method = express.Method;
+            string name = method.Name;
+            var args = express.Arguments.Cast<Expression>().ToList();
+            MethodCallExpressionModel model = new MethodCallExpressionModel();
+            model.Args = new List<MethodCallExpressionArgs>();
+            switch (this.Context.ResolveType)
+            {
+                case ResolveExpressType.WhereSingle:
+                case ResolveExpressType.WhereMultiple:
+                    if (express.Object != null)
+                        args.Insert(0,express.Object);
+                    Where(parameter, isLeft, name, args, model);
+                    break;
+                case ResolveExpressType.SelectSingle:
+                case ResolveExpressType.SelectMultiple:
+                case ResolveExpressType.Update:
+                    if (express.Object != null)
+                        args.Insert(0, express.Object);
+                    Select(parameter, isLeft, name, args, model);
+                    break;
+                case ResolveExpressType.FieldSingle:
+                case ResolveExpressType.FieldMultiple:
+                default:
+                    break;
+            }
+        }
+
+        private void Select(ExpressionParameter parameter, bool? isLeft, string name, IEnumerable<Expression> args, MethodCallExpressionModel model)
         {
             foreach (var item in args)
             {
@@ -51,11 +101,11 @@ namespace SqlSugar
             }
             parameter.BaseParameter.CommonTempData = GetMdthodValue(name, model);
         }
-        private void Where(ExpressionParameter parameter, bool? isLeft, string name, System.Collections.ObjectModel.ReadOnlyCollection<Expression> args, MethodCallExpressionModel model)
+        private void Where(ExpressionParameter parameter, bool? isLeft, string name, IEnumerable<Expression> args, MethodCallExpressionModel model)
         {
             foreach (var item in args)
             {
-                var isBinaryExpression = item is BinaryExpression||item is MethodCallExpression;
+                var isBinaryExpression = item is BinaryExpression || item is MethodCallExpression;
                 if (isBinaryExpression)
                 {
                     model.Args.Add(GetMethodCallArgs(parameter, item));