Abstract: Replication strategies directly effect on use of grid resources in data grid. As the replication strategies are very important to the data grid, this paper builds up a simulation environment with OptorSim simulators, and analyzes different replication strategies according to different accessing models. Reasearch of data structure of grid, replication strategies, policy of job scheduler, mode of access, and effect on data grid. It is verified by the simulation results that the replication strategies adopted in this paper can cut down the system cost of single operation and make the most use of computing unit.