when the demand of system productivity is increased, the throughput of AGV system is also needed to be developed. By adding more single-load AGVs in the system, more items can be transported at same time. But consequently, the traffic for AGVs becomes more congested, and tradeoff caused by number of AGV is difficult to balance. The multi-load AGV can transport more items at same time and no additional AGVs are necessarily involved. But the control of multi-load AGV is much more complicated than single-load one as realized as many aspects. In this paper, a simulation study of multi-load AGV system based on JIT production environment is presented, the purpose of which is to examine the improvement generated by multi-load AGV system in JIT production environment and the performance of it when higher demand of system productivity is met. The control of multi-load AGV system focuses on selection of requesting stations and items in different situations, and also the responding procedure. The results of experimental test indicate that the introduced multi-load AGV system is adaptive to JIT production system and able to provide much higher throughput to satisfy the increasing demand of productivity compared with single-load one.