RFID middleware plays an important role in extracting information from RFID reader and sending them to the terminal server. Although the traditional middleware technique solution of RFID can ensure the continuous operation of the system, the cost is too much CPU working load and serious waste of physical resources. The Agent that has played a central role in many application fields can also provide non-centralized and adaptive solutions for load balancing. The paper presented a RFID middleware load balancing method based on Agent according to characteristics of RFID middleware and designed adaptive load allocation algorithm. Two kinds of agents were design, namely information collection Agent and load balancing Agent, to collaborate to complete corresponding strategies of load balancing.