diff --git a/library/think/Cache.php b/library/think/Cache.php
index 10ff01c8..c7a48789 100644
--- a/library/think/Cache.php
+++ b/library/think/Cache.php
@@ -118,7 +118,7 @@ class Cache
      * @param int       $expire  有效时间 0为永久
      * @return false|int
      */
-    public function inc($name, $step = 1, $expire = null)
+    public static function inc($name, $step = 1, $expire = null)
     {
         self::init();
         self::$writeTimes++;
@@ -133,7 +133,7 @@ class Cache
      * @param int       $expire  有效时间 0为永久
      * @return false|int
      */
-    public function dec($name, $step = 1, $expire = null)
+    public static function dec($name, $step = 1, $expire = null)
     {
         self::init();
         self::$writeTimes++;
diff --git a/tests/thinkphp/library/think/cache/driver/cacheTestCase.php b/tests/thinkphp/library/think/cache/driver/cacheTestCase.php
index b280726f..3039024d 100644
--- a/tests/thinkphp/library/think/cache/driver/cacheTestCase.php
+++ b/tests/thinkphp/library/think/cache/driver/cacheTestCase.php
@@ -180,9 +180,16 @@ abstract class cacheTestCase extends \PHPUnit_Framework_TestCase
 
     public function testStaticCall()
     {
-        $this->assertTrue(Cache::set('a', 'a'));
-        $this->assertEquals('a', Cache::get('a'));
+        $this->assertTrue(Cache::set('a', 1));
+        $this->assertEquals(1, Cache::get('a'));
+        $this->assertEquals(2, Cache::inc('a'));
+        $this->assertEquals(4, Cache::inc('a', 2));
+        $this->assertEquals(4, Cache::get('a'));
+        $this->assertEquals(3, Cache::dec('a'));
+        $this->assertEquals(1, Cache::dec('a', 2));
+        $this->assertEquals(1, Cache::get('a'));
         $this->assertNotNull(Cache::rm('a'));
+        $this->assertNotNull(Cache::clear());
     }
 
 }