Using seasonal Kendall's test method and area homogeneity test method, the author tested the water_quality tendency of the Zuojiang_Youjiang_Yongjiang river, analyzed the cause and put forward water pollution prevention and harnessing countermeasures. 运用季节性肯达尔检验法和区域均一性检验法对左江、右江和邕江的水质趋势进行检验,并进行原因分析,提出水污染防治对策。