A three-dimensional modcl for simulating the dynamics of wind-driven lake current and water level in Taihu Lake was constructed. The water body can be divided into many layers in vertical direction. The fractions of layers arc the same for all the lake in the model. The dynamic processes of the currents and water level in Taihu Lake were simulated for 9 clays including the 9711 typhoon process in 18-20 Aug.,1997. The model was calibrated by the use of water level data of six hydrological stations surrounding the lake. The simulated lake currents were compared with the observed data of water current at the point in the mouth of Mciliang Bay. The simulation results on upwelling-downwclling of water level were coincidcd with the data observed at the six stations and the simulation results on lake current reflcctcd the main structure of observed data. The results of the model showed there were rapid changcs of current vcctors along vertical direction. The bottom lake currents are the compensation currents of the surfacc lake currents，which almost follow the wind direction.