diff --git a/src/main/java/com/alibaba/fastjson/JSON.java b/src/main/java/com/alibaba/fastjson/JSON.java
index 2bcff3a5dd..f33ed9787a 100755
--- a/src/main/java/com/alibaba/fastjson/JSON.java
+++ b/src/main/java/com/alibaba/fastjson/JSON.java
@@ -130,12 +130,24 @@ public static Object parse(String text) {
         return parse(text, DEFAULT_PARSER_FEATURE);
     }
 
-    public static Object parse(String text, int features) {
+    /**
+     *
+     * @since 1.2.38
+     */
+    public static Object parse(String text, ParserConfig config) {
+        return parse(text, config, DEFAULT_PARSER_FEATURE);
+    }
+
+    /**
+     *
+     * @since 1.2.38
+     */
+    public static Object parse(String text, ParserConfig config, int features) {
         if (text == null) {
             return null;
         }
 
-        DefaultJSONParser parser = new DefaultJSONParser(text, ParserConfig.getGlobalInstance(), features);
+        DefaultJSONParser parser = new DefaultJSONParser(text, config, features);
         Object value = parser.parse();
 
         parser.handleResovleTask(value);
@@ -145,6 +157,10 @@ public static Object parse(String text, int features) {
         return value;
     }
 
+    public static Object parse(String text, int features) {
+        return parse(text, ParserConfig.getGlobalInstance(), features);
+    }
+
     public static Object parse(byte[] input, Feature... features) {
         char[] chars = allocateChars(input.length);
         int len = IOUtils.decodeUTF8(input, 0, input.length, chars);
diff --git a/src/main/java/com/alibaba/fastjson/parser/DefaultJSONParser.java b/src/main/java/com/alibaba/fastjson/parser/DefaultJSONParser.java
index bacc821cff..525441e798 100755
--- a/src/main/java/com/alibaba/fastjson/parser/DefaultJSONParser.java
+++ b/src/main/java/com/alibaba/fastjson/parser/DefaultJSONParser.java
@@ -527,8 +527,10 @@ public final Object parseObject(final Map object, Object fieldName) {
                         ctxLocal.object = object;
                     }
 
-                    checkMapResolve(object, key.toString());
-
+                    if (key != null) {
+                        checkMapResolve(object, key.toString());
+                    }
+                    
                     map.put(key, obj);
 
                     if (parentIsArray) {
diff --git a/src/test/java/com/alibaba/json/bvt/issue_1500/Issue1503.java b/src/test/java/com/alibaba/json/bvt/issue_1500/Issue1503.java
new file mode 100644
index 0000000000..881e8f19b4
--- /dev/null
+++ b/src/test/java/com/alibaba/json/bvt/issue_1500/Issue1503.java
@@ -0,0 +1,24 @@
+package com.alibaba.json.bvt.issue_1500;
+
+import com.alibaba.fastjson.JSON;
+import com.alibaba.fastjson.parser.ParserConfig;
+import com.alibaba.fastjson.serializer.SerializerFeature;
+import junit.framework.TestCase;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class Issue1503 extends TestCase {
+    public void test_for_issue() throws Exception {
+        ParserConfig config = new ParserConfig();
+        config.setAutoTypeSupport(true);
+        Map<Long, Bean> map = new HashMap<Long, Bean>();
+        map.put(null, new Bean());
+        Map<Long, Bean> rmap = (Map<Long, Bean>) JSON.parse(JSON.toJSONString(map, SerializerFeature.WriteClassName), config);
+        System.out.println(rmap);
+    }
+
+    public static class Bean {
+
+    }
+}