The water currents in Taihu Lake driven by 8. 0 m/s SE, SW and NW wind were calculated by using the three-dimensional model，in which the water depth was normalized to 1, the water column equally divided into five layers and the time step and x，direction step were 120s and lkm respectively. Hencc, the lake currents developments and the average currents along the vertical direction were analyzed. The influences of wind stress, water pressure gradient force, frictional stress of Taihu Lake bottom on the vertical structure of water current were considered as well.The forming mechanism of vertical current structure was revealed initially. At the beginning of the wind, such as after.lh, the flow decreased gradually from surface to middle layer, but the deviation from the wind direction was small, no more than 20。，while in the middle to bottom layer, there was a small flow with a direction typically different from the wind direction. As time went by, with the water accumulated in the windward area，the water pressure gradient force became big, so the flow decreased at the surface layer and increased at the bottom layer. After a typical wind has dominated for 12h, a stable flow field was formed in the open Taihu Lake. At the surface layer the deviation angle of the flow in center Taihu Lake was about 20°, the current was evenly distributed and the flow was smaller than that after lh. At the layer under the surface layer the flow field distributed irregularly, with smaller flow when comparing with those on the surface and middle layer, and directions changed dramatically at different network points. At the middle layer, the flow field were evenly distributed, with an angle of more than 90° deviated from the wind direction. At the bottom layer and its upper layer, the flow field were also distributed evenly, with an direction adverse of the bottom flow, which were due to the compensation flow of the surface water flow. At the upper part of the bottom layer the flow was bigger than those on the bottom and middle layer.It was also shown that in the bay and semi-closed area flows were stable, even after the wind has blewn for 48 h. There were divergence and convergence on each layer. At the beginning,the divergence and convergence were strong. There was sinking area in the Ice side and upwelling area in the windward side. As time went by, the divergence became weak and the upwelling area became large,The model revealed that there existed wind-stress-dominated area, water-prcssure-force-dominated area and bottom-frietion-foree-dominated area vertically.