diff --git a/Apewer/UnparallelAttribute.cs b/Apewer/UnparallelAttribute.cs
index d5b39a2..5b2e89f 100644
--- a/Apewer/UnparallelAttribute.cs
+++ b/Apewer/UnparallelAttribute.cs
@@ -4,7 +4,7 @@ namespace Apewer
 {
 
     /// <summary>表示方法不可并行。</summary>
-    [AttributeUsage(AttributeTargets.Method)]
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)]
     public sealed class UnparallelAttribute : Attribute
     {
 
diff --git a/Apewer/Web/ApiApplication.cs b/Apewer/Web/ApiApplication.cs
index 6d5b348..7850eb3 100644
--- a/Apewer/Web/ApiApplication.cs
+++ b/Apewer/Web/ApiApplication.cs
@@ -22,6 +22,7 @@ namespace Apewer.Web
         // invoke & enumerate
         bool _independent = false;
         bool _hidden = false;
+        bool _unparallel = false;
 
         // functions
         Dictionary<string, ApiFunction> _dict = new Dictionary<string, ApiFunction>();
@@ -52,6 +53,9 @@ namespace Apewer.Web
         /// <summary></summary>
         public bool Hidden { get => _hidden; }
 
+        /// <summary></summary>
+        public bool Unparallel { get => _unparallel; }
+
         /// <summary></summary>
         public ApiFunction[] Functions { get => _list.ToArray(); }
 
@@ -98,6 +102,9 @@ namespace Apewer.Web
                 // independent
                 if (type.Contains<IndependentAttribute>(false)) _independent = true;
 
+                // unparallel
+                if (type.Contains<UnparallelAttribute>(false)) _unparallel = true;
+
                 // Module
                 var assemblyName = type.Assembly.GetName();
                 _module = TextUtility.Join("-", assemblyName.Name, assemblyName.Version.ToString());
diff --git a/Apewer/Web/ApiFunction.cs b/Apewer/Web/ApiFunction.cs
index 885ca94..b615bf0 100644
--- a/Apewer/Web/ApiFunction.cs
+++ b/Apewer/Web/ApiFunction.cs
@@ -22,6 +22,7 @@ namespace Apewer.Web
         string _description = null;
 
         bool _hidden = false;
+        bool _unparallel = false;
 
         #endregion
 
@@ -51,6 +52,9 @@ namespace Apewer.Web
         /// <summary></summary>
         public bool Hidden { get => _hidden; }
 
+        /// <summary></summary>
+        public bool Unparallel { get => _unparallel; }
+
         #endregion
 
         /// <summary></summary>
@@ -118,6 +122,9 @@ namespace Apewer.Web
             // hidden
             if (method.Contains<HiddenAttribute>(false)) _hidden = true;
 
+            // unparallel
+            if (method.Contains<UnparallelAttribute>(false)) _unparallel = true;
+
             // 参数。
             _parameters = parameters;
         }
diff --git a/Apewer/Web/ApiProcessor.cs b/Apewer/Web/ApiProcessor.cs
index dec3352..d174368 100644
--- a/Apewer/Web/ApiProcessor.cs
+++ b/Apewer/Web/ApiProcessor.cs
@@ -404,12 +404,25 @@ namespace Apewer.Web
                 }
                 else
                 {
+
                     // 创建默认控制器。
                     var controller = null as ApiController;
                     try
                     {
-                        controller = CreateController(@default, _context);
-                        InvokeFunction(controller, application, null, options, request, response);
+                        var unparallel = @default.Contains<UnparallelAttribute>(false);
+                        if (unparallel)
+                        {
+                            UnparallelLocker.InLock(GetUnparallelKey(@default), () =>
+                            {
+                                controller = CreateController(@default, _context);
+                                InvokeFunction(controller, application, null, options, request, response);
+                            });
+                        }
+                        else
+                        {
+                            controller = CreateController(@default, _context);
+                            InvokeFunction(controller, application, null, options, request, response);
+                        }
                     }
                     catch (Exception ex)
                     {
@@ -428,8 +441,27 @@ namespace Apewer.Web
                 var controller = null as ApiController;
                 try
                 {
-                    controller = CreateController(application.Type, _context);
-                    InvokeFunction(controller, application, function, options, request, response);
+                    if (application.Unparallel)
+                    {
+                        UnparallelLocker.InLock(GetUnparallelKey(application.Type), () =>
+                        {
+                            controller = CreateController(application.Type, _context);
+                            InvokeFunction(controller, application, function, options, request, response);
+                        });
+                    }
+                    else if (function != null && function.Unparallel)
+                    {
+                        UnparallelLocker.InLock(GetUnparallelKey(function.Method), () =>
+                        {
+                            controller = CreateController(application.Type, _context);
+                            InvokeFunction(controller, application, function, options, request, response);
+                        });
+                    }
+                    else
+                    {
+                        controller = CreateController(application.Type, _context);
+                        InvokeFunction(controller, application, function, options, request, response);
+                    }
                 }
                 catch (Exception ex)
                 {
@@ -831,7 +863,7 @@ namespace Apewer.Web
 
         static string GetUnparallelKey(Type type)
         {
-            return $"{type.DeclaringType.Assembly.ToString()}";
+            return $"{type.Assembly.ToString()} | {type.FullName}";
         }
 
         #endregion