This dissertation focused on the organic pesticides' environmental behavior and its effects in the estuarine agricultural watershed. We chose the Wuchuan watershed (WCW, one little branch of Jiulong River watershed, did sampling in July, Sep., Nov.,2000 and runoff sampling in Dec.,2000) and Jiulong River Estuary(JLRE, one cruise in Dec.,2000) as our study areas. And the organic pesticides focused on 18 Organic chlorine pesticides (Ocls) and 17 Organic phosphorus pesticides (OPPs). The results are...