Abstract: The pollution characteristics of eight therapeutic groups, including antibiotics, analgesics, antiepileptics, antilipidemics, antihypersensitives, in the Yangtze River, Jialing River and Huaxi stream which is a tributary of the Yangtze River in Chongqing, were investigated using the high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. Results showed that 14of the 21target PhACs were detected and the concentration levels ranged from 1.1to 35.5ng/L in the Yangtze River and Jialing River, while ranged from 10.3to 445.6ng/L in the Huaxi stream. Moxifloxacin, bezafibrate, gemfibrozil, diclofenac and atorvastatin were only detected in the Huaxi stream. The concentrations varied from 0.6-31.4ng/L. Amlodipine was not found in this study. The flow of Huaxi stream is small and the direct emission of the surrounding sewage was very serious. Consequently, the concentrations of the target PhACs, except for sulfamethazine, carbamazepine and simvastatin, in Huaxi stream were statistically significantly higher than in the other two rivers. Risk quotients, the ratios of measured environmental concentrations (MEC) and the predicted no-effect concentrations, were over than 0.1for sulfamethoxazole, ofloxacin, erythromycin and clofibric acid, indicating that the environment concentrations of single compounds may have a medium ecological risk, which is closely related to their larger consumption.