diff --git a/mysql-test/suite/tianmu/r/composite_primary_key.result b/mysql-test/suite/tianmu/r/composite_primary_key.result
new file mode 100644
index 000000000..de7810415
--- /dev/null
+++ b/mysql-test/suite/tianmu/r/composite_primary_key.result
@@ -0,0 +1,9 @@
+DROP DATABASE IF EXISTS composite_primary_key_test;
+CREATE DATABASE composite_primary_key_test;
+USE composite_primary_key_test;
+create table ttt(id int,c1 varchar(10),c2 varchar(10),primary key(id,c1)) ENGINE=TIANMU;
+insert into ttt values(1,'xxx','xxx');
+insert into ttt values(1,'','xxx');
+insert into ttt values(1,'','xxx');
+ERROR 23000: Duplicate entry '1-' for key 'PRIMARY'
+DROP DATABASE composite_primary_key_test;
diff --git a/mysql-test/suite/tianmu/t/composite_primary_key.test b/mysql-test/suite/tianmu/t/composite_primary_key.test
new file mode 100644
index 000000000..dc6c782ad
--- /dev/null
+++ b/mysql-test/suite/tianmu/t/composite_primary_key.test
@@ -0,0 +1,25 @@
+--source include/have_tianmu.inc
+
+--disable_warnings
+DROP DATABASE IF EXISTS composite_primary_key_test;
+--enable_warnings
+
+CREATE DATABASE composite_primary_key_test;
+
+USE composite_primary_key_test;
+
+--disable_warnings
+
+## DDL
+create table ttt(id int,c1 varchar(10),c2 varchar(10),primary key(id,c1)) ENGINE=TIANMU;
+
+## insert data
+insert into ttt values(1,'xxx','xxx');
+
+insert into ttt values(1,'','xxx');
+--error ER_DUP_ENTRY
+insert into ttt values(1,'','xxx');
+
+
+## clean test table
+DROP DATABASE composite_primary_key_test;
diff --git a/storage/tianmu/index/rdb_meta_manager.cpp b/storage/tianmu/index/rdb_meta_manager.cpp
index df1183800..54b78a38c 100644
--- a/storage/tianmu/index/rdb_meta_manager.cpp
+++ b/storage/tianmu/index/rdb_meta_manager.cpp
@@ -127,6 +127,10 @@ common::ErrorCode RdbKey::unpack_field_number(StringReader &key, std::string &fi
 }
 
 void RdbKey::pack_field_string(StringWriter &info, StringWriter &key, std::string &field) {
+  // issue1374: bug: Failed to insert a null value to the composite primary key.
+  // the empty field of primary key will be ignored.
+  if (field.length() == 0)
+    return;
   // version compatible
   if (index_ver_ == static_cast<uint16_t>(IndexInfoType::INDEX_INFO_VERSION_INITIAL)) {
     key.write((const uchar *)field.data(), field.length());