Abstract: Shallow lakes are important freshwater resources and have the functions of flood, transportation, agriculture, aquaculture, tourism, drinking and ecological protection. The environmental quality of shallow lakes is highly related to human health and sustainable development of social economy. Rapid urbanization and economic development have resulted, progressively, in deteriorating freshwater conditions. Lake Taihu is the third largest freshwater lake in China. In order to characterize the the pollution characteristics of organochlorine pesticides in surface sediments of Lake Taihu, 32 and 79 sediment samples were collected in May 2013 from Lake Taihu and its tributary rivers,respectively. The contents of twenty organochlorine pesticides in the samples were analyzed by GC-μECD and the risk of sediment contamination was evaluated using sediment quality guidelines(SQGs). The results showed that OCPs were detected in all sediment samples, with residual values ranging from 16.3 to 96.9 ng/g dw, and the average content was 35.0 ng/g dw. HCHs and DDTs were the major components, and the average contents were 12.1 and 7.6 ng/g dw, respectively. The content of HCHs and DDTs accounted for 25.5% to 85.5% of the total OCPs. The ratios of certain metabolites to their parent compounds indicated that the main source of HCHs was lindane, and lindane is  still in use recently. There are still new inputs of parent DDT compound in Taihu Lake Basin, which might come from antifouling paints in fishing ships or other pesticides containing DDT, such as dicofol. A sediment risk assessment based on sediment quality guidelines(SQGs) suggested that γ-HCH and DDTs could be potential contaminants of greater ecotoxicological concern.