RAM(random access memory)Grid is a new grid system aiming at memory resources sharing in wide-area network;it can improve the performance of memory intensive or IO intensive applications when lack of physical memory.Reducing or hiding the network overhead can improve the performance of RAM Grid,which lies on the overhead of network communication.In this paper,through the analysis of RAM Grid,a “push” based prefetching mechanism is proposed for it.The corresponding prefetching algorithm,which comes from the sequential pattern mining method in data mining area,is also raised.The prefetching algorithm is evaluated and proved by trace driven simulation.