Exploring the response mechanism of water ecosystem services to the change of watershed landscape pattern in rapidly urbanization is of great significance to watershed landscape planning and ecosystem service improvement. This study took the Taihu Lake Basin as the research area, based on land use data, models and methods such as comprehensive landscape pattern index, SCS and InVEST model, and partial correlation analysis were applied. On the basis of depicted the landscape pattern and the spatial differentiation characteristics of three typical water ecosystem services, which were stormwater regulation, soil and water conservation and water quality purification, the response relationship of water ecosystem services to the characteristics of different landscape patterns at sub-watershed scale was mainly discussed. The results showed that: among the impact of the composition and configuration of the landscape on the three typical water ecosystem services, most of the conclusions were consistent with existing research conclusions or understanding. However, it was also found that the complexity of the shape of cultivated land and woodland landscape patches in Taihu Lake basin could improve the river water quality, and the wetland rare patches in the sub-basin were conducive to reducing non-point source pollution. The three kinds of water ecosystem services could be effectively improved by controlling the scale of cultivated land, optimizing the distance between cultivated land and water body and reducing slope cultivated land. Increasing forestland area in waterfront area and improving the density of patch edge, increasing the proportion of wetland and grassland in sub-basin were conducive to better control water pollution. Increasing the key landscape types such as wetlands and grasslands was the most effective way to improve water purification services. In order to more comprehensively and accurately depict the response relationship between pattern and water ecosystem service, it is also necessary to carry out in-depth research on ecosystem service flow, non-linear relationship and threshold, and the relative contribution of different pattern characteristics to service.