Nowadays, RFID (Radio Frequency Identification) mobile middleware technology is gaining growing attention due to its competitive business prospect and value. With the ability to be automatically identified and collect information, RFID mobile systems have been applied to various fields. Meanwhile, advancements in wireless communication technology have greatly increased the functionality of mobile RFID information services and have made many mobile computing applications a reality. In this paper, we focus on the study of the inconsistency problem between update and read transactions. Data items on server being concurrently modified without any control may turn to be "dirty". If the executions of update and read transactions are interleaved without any mechanism to assist, it is possible that the mobile transactions, which generated by mobile clients, may observe inconsistent data values. To solve this problem, we propose a framework for lightweight data synchronization on mobile RFID devices, for concurrency control among read and update transactions. Data is classified according to its permissions assigned to mobile clients. All the schedules among transactions that are regulated to be stored in a corresponding pool are in serialization. Moreover, due to rebroadcast mechanism, reading transactions never need a lock before reading data items. The transaction cluster division and conflict detection only for every transaction cluster can enhance the practicality and flexibility of the mobile RFID system.