diff --git a/Data~/hybridclr_version.json b/Data~/hybridclr_version.json
index 21d49b0..f7386cb 100644
--- a/Data~/hybridclr_version.json
+++ b/Data~/hybridclr_version.json
@@ -1,13 +1,18 @@
 {
     "versions": [
+    {
+        "unity_version":"2020",
+        "hybridclr" : { "branch":"v3.0.3"},
+        "il2cpp_plus": { "branch":"v2020-3.0.0"}
+    },
     {
         "unity_version":"2021",
-        "hybridclr" : { "branch":"v3.0.2"},
+        "hybridclr" : { "branch":"v3.0.3"},
         "il2cpp_plus": { "branch":"v2021-3.0.1"}
     },
     {
         "unity_version":"2022",
-        "hybridclr" : { "branch":"v3.0.2"},
+        "hybridclr" : { "branch":"v3.0.3"},
         "il2cpp_plus": { "branch":"v2022-3.0.1"}
     }
     ]
diff --git a/Editor/Installer/InstallerController.cs b/Editor/Installer/InstallerController.cs
index 8db12e9..b301f9b 100644
--- a/Editor/Installer/InstallerController.cs
+++ b/Editor/Installer/InstallerController.cs
@@ -74,6 +74,7 @@ namespace HybridCLR.Editor.Installer
 
         private static readonly Regex s_unityVersionPat = new Regex(@"(\d+)\.(\d+)\.(\d+)");
 
+        public const int min2020_3_CompatibleMinorVersion = 26;
         public const int min2021_3_CompatibleMinorVersion = 0;
         public const int min2022_3_CompatibleMinorVersion = 0;
 
@@ -111,22 +112,22 @@ namespace HybridCLR.Editor.Installer
         public bool IsComaptibleVersion()
         {
             UnityVersion version = _curVersion;
+            if (version.minor1 != 3)
+            {
+                return false;
+            }
             switch (version.major)
             {
+                case 2020:
+                    {
+                        return version.minor2 >= min2021_3_CompatibleMinorVersion;
+                    }
                 case 2021:
                     { 
-                        if (version.minor1 != 3)
-                        {
-                            return false;
-                        }
                         return version.minor2 >= min2021_3_CompatibleMinorVersion;
                     }
                 case 2022:
                     {
-                        if (version.minor1 != 3)
-                        {
-                            return false;
-                        }
                         return version.minor2 >= min2022_3_CompatibleMinorVersion;
                     }
                 default: throw new Exception($"not support il2cpp_plus branch:{version.major}");