diff --git a/README.md b/README.md
index bb52d3d..a4ff4d9 100644
--- a/README.md
+++ b/README.md
@@ -665,7 +665,7 @@ public function get(string $key, $default = null)
 `beforeOrEqualDate` | 字段值必须是小于或等于给定日期的值 | `['publishedAt', 'beforeOrEqualDate', '2017-05-12']`
 `afterOrEqualDate` | 字段值必须是大于或等于给定日期的值 | `['publishedAt', 'afterOrEqualDate', '2017-05-12']`
 `afterDate` | 验证字段值必须是给定日期之前的值 | `['publishedAt', 'afterDate', '2017-05-12']`
-`json`   | 验证是否是json字符串 | `['goods', 'json']`
+`json`   | 验证是否是json字符串(默认严格验证，必须以`{` `[` 开始) | `['goods', 'json']` `['somedata', 'json', false]` - 非严格，普通字符串`eg 'test'`也会通过
 `file`   | 验证是否是上传的文件 | `['upFile', 'file']`
 `image`   | 验证是否是上传的图片文件 | `['avatar', 'image']`, 限定后缀名 `['avatar', 'image', 'jpg,png']`
 `ip`    | 验证是否是 IP | `['ipAddr', 'ip']`
diff --git a/src/ValidatorList.php b/src/ValidatorList.php
index 136af12..bc5a29d 100644
--- a/src/ValidatorList.php
+++ b/src/ValidatorList.php
@@ -645,15 +645,21 @@ public static function strList($val)
     /**
      * 验证字段值是否是一个有效的 JSON 字符串。
      * @param  string $val
+     * @param bool $strict
      * @return bool
      */
-    public static function json($val)
+    public static function json($val, $strict = true)
     {
         if (!$val || (!\is_string($val) && !method_exists($val, '__toString'))) {
             return false;
         }
 
-        json_decode($val);
+        // must start with: { OR [
+        if ($strict && '[' !== $val[0] && '{' !== $val[0]) {
+            return false;
+        }
+
+        json_decode((string)$val);
 
         return json_last_error() === JSON_ERROR_NONE;
     }
diff --git a/tests/RuleValidationTest.php b/tests/RuleValidationTest.php
index df5d79d..9255a31 100644
--- a/tests/RuleValidationTest.php
+++ b/tests/RuleValidationTest.php
@@ -95,6 +95,28 @@ public function testValidateString()
         $this->assertEquals($v->getSafe('user_name'), $val);
     }
 
+    public function testValidateJson()
+    {
+        $v = Validation::make([
+            'log_level' => 'debug',
+            'log_data' => '[23]',
+            'log_data1' => '234',
+        ], [
+            ['log_level, log_data', 'required'],
+            ['log_level, log_data', 'string'],
+            ['log_data', 'json'],
+            ['log_data1', 'json', false],
+        ])->validate();
+
+        // var_dump($v->getErrors());
+        $this->assertTrue($v->passed());
+        $this->assertFalse($v->failed());
+
+        $errors = $v->getErrors();
+        $this->assertEmpty($errors);
+        $this->assertCount(0, $errors);
+    }
+
     protected function someRules()
     {
         return [
diff --git a/tests/ValidatorListTest.php b/tests/ValidatorListTest.php
index 4d91464..7c26c98 100644
--- a/tests/ValidatorListTest.php
+++ b/tests/ValidatorListTest.php
@@ -245,4 +245,20 @@ public function testStrList()
         $this->assertTrue(ValidatorList::strList(['abc']));
         $this->assertTrue(ValidatorList::strList(['abc', 565, null]));
     }
+
+    public function testJson()
+    {
+        $this->assertFalse(ValidatorList::json('test'));
+        $this->assertFalse(ValidatorList::json([]));
+
+        $this->assertFalse(ValidatorList::json(123));
+        $this->assertFalse(ValidatorList::json('123'));
+        $this->assertTrue(ValidatorList::json('123', false));
+
+        $this->assertFalse(ValidatorList::json('{aa: 34}'));
+
+        $this->assertTrue(ValidatorList::json('{}'));
+        $this->assertTrue(ValidatorList::json('[]'));
+        $this->assertTrue(ValidatorList::json('{"aa": 34}'));
+    }
 }
diff --git a/tests/boot.php b/tests/boot.php
index fe9000a..b8dfdcb 100644
--- a/tests/boot.php
+++ b/tests/boot.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * phpunit6.phar --bootstrap tests/bootstap.php tests
+ * phpunit6.phar --bootstrap tests/boot.php tests
  */
 
 require dirname(__DIR__) . '/examples/simple-loader.php';