Abstract: The parallel groundwater model for 2D unsteady seepage flow with finite element method is established. The message passing interface is applied to simulate saturated unsaturated seepage flow on Windows NT. To solve the el iptic differential equation,the implicit numerical scheme is applied and a parallel generalized minimal residual algorithm is used to solve the large sparse linear system. In order to improve the performance of the parallel program,multiple techniques are used,such as load balance,communication improvement and global operations. To verify the model,the seepage flows through the coffer dam of Xiluodu hydropower station and two kinds of unsteady seepage flows are simulated The results obtained are reasonable. In the end,the speedup of the parallel comput ing model is evaluated. It can be seen that bet er parallel performance is achieved as the computat ional scale increases.