Objective To understand the microcystin(MC-LR)pollution in drinking water in the city and countryside of Fuling District,Sichuan,China.Methods In 2004,285 water samples were collected from different types of water in Fuling district in different season and the concentration of LR(MC-LR),total phosphorus and total nitrogen in water were determined respectively.Results From July to November in 2004,no LR(MC-LR)was detected and the total phosphorus and total nitrogen did not exceed the national standard limits in the drinking water in the city,but in the secondary water supply in the city,the MC-LR was detected,the total phosphorus and total nitrogen exceed the standard limits.In the countryside,the MC-LR was detected,the total phosphorus and total nitrogen exceed the standard limits.Conclusion In the countryside of Fuling District,Sichuan,China,the drinking water,water source and tap water,was seriously contaminated by microcystin,the total phosphorus and total nitrogen exceed the national standard limits.