diff --git a/src/main/java/util/ByteHelper.java b/src/main/java/util/ByteHelper.java
index be71309..2475796 100644
--- a/src/main/java/util/ByteHelper.java
+++ b/src/main/java/util/ByteHelper.java
@@ -49,13 +49,15 @@ public class ByteHelper {
     public static byte[] getLenBytes(byte[] buffer, VlInt start,VlInt len){
         int startInt=start.getVlIntValue2Int();
         int lenInt=len.getVlIntValue2Int();
-        byte[] lenbytes=new byte[1];
+        byte[] lenbytes=new byte[lenInt];
+//        byte[] lenbytes=new byte[1];
         System.arraycopy(buffer,startInt,lenbytes,0,lenInt);
         return lenbytes;
     }
     public static byte[] getLenBytes(byte[] buffer, VlInt start,int len){
         int startInt=start.getVlIntValue2Int();
-        byte[] lenbytes=new byte[1];
+        byte[] lenbytes=new byte[len];
+//        byte[] lenbytes=new byte[1];
         System.arraycopy(buffer,startInt,lenbytes,0,len);
         return lenbytes;
     }
diff --git a/src/test/java/util/ByteHelperTest.java b/src/test/java/util/ByteHelperTest.java
index e6db963..689b53e 100644
--- a/src/test/java/util/ByteHelperTest.java
+++ b/src/test/java/util/ByteHelperTest.java
@@ -29,7 +29,7 @@ import static org.junit.Assert.*;
         assertArrayEquals(b2,test2);
     }
 
-    //error
+    //todo:对start值进行限定，应当小于Byte数组的length
     @Test
     public void getFirstByte() {
         byte[] b0 = new byte[]{0x00,0x00,0x01};
@@ -42,6 +42,14 @@ import static org.junit.Assert.*;
     //error
     @Test
     public void getLenBytes() {
+        byte[] buffer = new byte[]{0x00,0x00,0x01, (byte) 0xff};  //255
+        byte[] test = new byte[]{0x00,0x00,0x01};
+        VlInt start = new VlInt(0);
+        VlInt len = new VlInt(3);
+        byte[]b1 = ByteHelper.getLenBytes(buffer,start,len);
+        byte[] b2= ByteHelper.getLenBytes(buffer,start,3);
+        assertArrayEquals(test,b1);
+        assertArrayEquals(test,b2);
     }
 
 //    @Test