diff --git a/plugins/baser-core/src/Utility/BcLang.php b/plugins/baser-core/src/Utility/BcLang.php
index 842018982f..12ee0fd491 100644
--- a/plugins/baser-core/src/Utility/BcLang.php
+++ b/plugins/baser-core/src/Utility/BcLang.php
@@ -99,6 +99,7 @@ public function isMatchDecisionKey()
      * @return array|string
      * @checked
      * @noTodo
+     * @unitTest
      */
     static public function parseLang($acceptLanguage)
     {
@@ -121,5 +122,5 @@ static public function parseLang($acceptLanguage)
         }
         return $langs[0];
     }
-    
+
 }
diff --git a/plugins/baser-core/tests/TestCase/Utility/BcLangTest.php b/plugins/baser-core/tests/TestCase/Utility/BcLangTest.php
new file mode 100644
index 0000000000..d09e64aaf4
--- /dev/null
+++ b/plugins/baser-core/tests/TestCase/Utility/BcLangTest.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace BaserCore\Test\TestCase\Utility;
+
+use BaserCore\TestSuite\BcTestCase;
+use BaserCore\Utility\BcLang;
+
+class BcLangTest extends BcTestCase
+{
+    public function setUp(): void
+    {
+        parent::setUp();
+    }
+
+    public function tearDown(): void
+    {
+        parent::tearDown();
+    }
+
+    public function testSetConfig()
+    {
+        $this->markTestIncomplete('このテストは、まだ実装されていません。');
+    }
+
+    public function testGetDefaultConfig()
+    {
+        $this->markTestIncomplete('このテストは、まだ実装されていません。');
+    }
+
+    public function testGetPattern()
+    {
+        $this->markTestIncomplete('このテストは、まだ実装されていません。');
+    }
+
+    /**
+     * Test parseLang
+     * @dataProvider parseLangDataProvider
+     */
+    public function testParseLang($acceptLanguage, $expected)
+    {
+        $result = BcLang::parseLang($acceptLanguage);
+        $this->assertEquals($expected, $result);
+    }
+
+    public static function parseLangDataProvider()
+    {
+        return [
+            [null, 'ja'],
+            ['', 'ja'],
+            ['en-US', 'en'],
+            ['fr-CH, fr;q=0.9, en;q=0.8, de;q=0.7, *;q=0.5', 'fr'],
+            ['en-US,en;q=0.9', 'en'],
+            ['zh-CN,zh;q=0.9,en-US;q=0.8,en;q=0.7', 'zh'],
+            ['en-US,en;q=0.8,es-ES;q=0.5,es;q=0.3', 'en'],
+            ['123,456', '123'],
+        ];
+    }
+}