diff --git a/Storage/Storage.Test/RelationTest.cs b/Storage/Storage.Test/RelationTest.cs
new file mode 100644
index 0000000..6cd8982
--- /dev/null
+++ b/Storage/Storage.Test/RelationTest.cs
@@ -0,0 +1,46 @@
+using NUnit.Framework;
+using LeanCloud;
+using System.Threading.Tasks;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace LeanCloudTests {
+    public class RelationTest {
+        [SetUp]
+        public void SetUp() {
+            Utils.InitNorthChina();
+        }
+
+        [Test]
+        public async Task CreateRelation() {
+            AVObject tag1 = new AVObject("Tag") {
+                ["name"] = "hello"
+            };
+            await tag1.SaveAsync();
+            AVObject tag2 = new AVObject("Tag") {
+                { "name", "world" }
+            };
+            await tag2.SaveAsync();
+            AVObject todo = new AVObject("Todo");
+            AVRelation<AVObject> relation = todo.GetRelation<AVObject>("tags");
+            relation.Add(tag1);
+            relation.Add(tag2);
+            await todo.SaveAsync();
+        }
+
+        [Test]
+        public async Task QueryRelation() {
+            AVQuery<AVObject> query = new AVQuery<AVObject>("Todo");
+            query.OrderByDescending("createdAt");
+            AVObject todo = await query.FirstAsync();
+            AVRelation<AVObject> relation = todo.GetRelation<AVObject>("tags");
+            AVQuery<AVObject> tagQuery = relation.Query;
+            IEnumerable<AVObject> tags = await tagQuery.FindAsync();
+            Assert.Greater(tags.Count(), 0);
+            TestContext.Out.WriteLine($"count: {tags.Count()}");
+            foreach (AVObject tag in tags) {
+                TestContext.Out.WriteLine($"{tag.ObjectId}, {tag["name"]}");
+            }
+        }
+    }
+}
diff --git a/Storage/Storage.Test/Storage.Test.csproj b/Storage/Storage.Test/Storage.Test.csproj
index 50c6279..55e014f 100644
--- a/Storage/Storage.Test/Storage.Test.csproj
+++ b/Storage/Storage.Test/Storage.Test.csproj
@@ -8,9 +8,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="nunit" Version="3.11.0" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.11.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
+    <PackageReference Include="nunit" Version="3.12.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="3.15.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.2" />
   </ItemGroup>
 
diff --git a/Storage/Storage/Public/AVRelation.cs b/Storage/Storage/Public/AVRelation.cs
index d66ba80..739a80b 100644
--- a/Storage/Storage/Public/AVRelation.cs
+++ b/Storage/Storage/Public/AVRelation.cs
@@ -3,10 +3,7 @@ using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics;
-using System.Linq;
 using System.Linq.Expressions;
-using System.Reflection;
-using System.Text;
 
 namespace LeanCloud {
     /// <summary>