diff --git a/contracts/chip1155/BEChip1155.sol b/contracts/chip1155/BEChip1155.sol
index d362e26..d58b776 100644
--- a/contracts/chip1155/BEChip1155.sol
+++ b/contracts/chip1155/BEChip1155.sol
@@ -172,6 +172,16 @@ contract BEChip1155 is ERC1155, AccessControl {
         return lockedTokens[id];
     }
 
+    function isLockedBatch(uint256[] memory ids) external view 
+      returns (bool[] memory) {
+        uint256 len = ids.length;
+        bool[] memory results = new bool[](len);
+        for (uint256 i = 0; i < len; ++i) {
+          results[i] = lockedTokens[ids[i]];
+        }
+        return results;
+    }
+
     /**
      * @dev See {ERC1155-_beforeTokenTransfer}.
      */
@@ -185,6 +195,9 @@ contract BEChip1155 is ERC1155, AccessControl {
     ) internal virtual override {
         super._beforeTokenTransfer(operator, from, to, ids, amounts, data);
         uint256 len = ids.length;
+        for (uint256 i = 0; i < len; ++i) {
+            require(!lockedTokens[ids[i]], "Can not transfer locked token");
+        }
         if (from == address(0)) {
             // mint nft
             for (uint256 i = 0; i < len; ++i) {
@@ -246,12 +259,18 @@ contract BEChip1155 is ERC1155, AccessControl {
         uint256 page
     ) external view returns (TokenStruct[] memory) {
         uint256 size = _ownedTokens[user].length;
-        TokenStruct[] memory results = new TokenStruct[](page);
+        uint256 max = size;
+        uint256 pageSize = 0;
         if (start < size) {
-            uint256 max = size;
-            if (start + page < size) {
-                max = start + page;
-            }
+          if (start + page < size) {
+            pageSize = page;
+            max = start + page;
+          } else {
+            pageSize = size - start;
+          }
+        }
+        TokenStruct[] memory results = new TokenStruct[](pageSize);
+        if (pageSize > 0) {
             for (uint256 i = start; i < max; ++i) {
                 TokenStruct memory dataObj;
                 uint256 tokenId = _ownedTokens[user][i];