The three residential quarters of Shenxiang, Guangfeng and Huaiguhaoting in Wuxi City were selected as the research areas,and water quality and quantity were synchronously monitored for the runoff drainage processes of 13 different rainfallevents between 1st July and 23th September, 2014.This paper analyzed the main surface runoff pollutants in the urban areas ofWuxi, and compared the correlations between rainfall characteristics and event mean concentration of pollutants. The initial flusheffect was also studied on typical rainfall events. The results indicate that surface runoff pollution is still serious despite thereconstruction project of rain and sewage diversion has been accomplished in the selected areas, and the main pollutants includeCOD、NH3 -N and TP. Besides, the EMC has a significant positive correlation with rainfall density while it has not obviouscorrelation with other characteristics. In addition, the density in the early stage of rainfall affects greatly on initial flush effect.