The study area is a floodplain interlaced with a network of canals and ditches, and the shallow groundwater and surface water interactions in the study area are difficult to observe and measure. To study the impact of the shallow groundwater and surface water interactions on the quality of the shallow groundwater in surrounding area of Taihu Lake, we compared the concentrations of the 14 OCPs in some shallow groundwater samples from the same sub-study area with different distance to Taihu Lake.