diff --git a/README.md b/README.md
index 985f16c..5a18aef 100644
--- a/README.md
+++ b/README.md
@@ -170,6 +170,40 @@ public class MyTestClass
 ```
 
 
+#### UnityVersion
+
+`UnityVersionAttribute` is an NUnit test attribute class to skip test run if Unity version is older and/or newer than specified.
+
+This attribute can attached to test method, test class (`TestFixture`) and test assembly.
+Can be used with sync Test, async Test, and UnityTest.
+
+Usage:
+
+```csharp
+using System;
+using NUnit.Framework;
+using TestHelper.Attributes;
+
+[TestFixture]
+public class MyTestClass
+{
+    [Test]
+    [UnityVersion(newerThanOrEqual: "2022")]
+    public void MyTestMethod()
+    {
+        // Test run only for Unity 2022.1.0f1 or later.
+    }
+
+    [Test]
+    [UnityVersion(olderThan: "2019.4.0f1")]
+    public void MyTestMethod()
+    {
+        // Test run only for Unity older than 2019.4.0f1.
+    }
+}
+```
+
+
 #### CreateScene
 
 `CreateSceneAttribute` is an NUnit test attribute class to create new scene before running test.
diff --git a/Runtime/Attributes/UnityVersionAttribute.cs b/Runtime/Attributes/UnityVersionAttribute.cs
index 9e7f9e4..5b9a50b 100644
--- a/Runtime/Attributes/UnityVersionAttribute.cs
+++ b/Runtime/Attributes/UnityVersionAttribute.cs
@@ -20,6 +20,7 @@ public class UnityVersionAttribute : NUnitAttribute, IApplyToTest
 
         /// <summary>
         /// Skip this test run if Unity version is older and/or newer than specified.
+        /// Valid format, e.g., "2023.2.16f1", "2023.2", and "2023".
         /// </summary>
         /// <param name="newerThanOrEqual">This test will run if the Unity editor version is newer than or equal the specified version.</param>
         /// <param name="olderThan">This test will run if the Unity editor version is older than the specified version.</param>