Liuxihe River was one of the most important rivers in Guangzhou and about 60% drinking water of Guangzhou city was supplied by this river. In order to investigate the water quality of Liuxihe River, seven sampling sites were set along the river and water quality parameters were analyzed monthly in 2003. The water quality status in the upstream site Liangkou was much better than that in the downstream site Nangang throughout the year. Most of the parameters in Nangang had exceeded the water quality standard Ⅱ including DO, CODMn, BOD₅, NH₃-N and TP. Among these parameters, DO was the worst item and the maximum value of it was only 4.94mgL. Water quality was worse in dry season than that in flood season. From Liangkou to Nangang, the pH and DO declined gradually while CODMn, BOD₅, NH₃-N, TP increased. The results showed that water quality in the downstream of Liuxihe River had been polluted by organic matter.