Abstract: In order to protect the water environment of Xiangjiang River scientifically and effectively, and quantitative identify the main driving factors of water quality. In this paper, the Mann Kendall was used to analyze the water environment evolution trend of Xiangjiang river trunk stream, the stepwise regression analysis methods were used to determines the main driving factors of water quality indexes in different regions, which is based on water quality monitoring data from 1990 to 2016 and socioeconomic development indicators of cities along the coast. The results show that COD_Mn, Cd and As was downtrend, BOD₅ shows an downtrend in the upper reaches, the pollution of NH₃-N in the upper and middle reaches shows an upward trend,TP in Hengyang shows an upward trend, in the middle reaches of Hengyang and Zhuzhou regions, heavy metal Cr⁶⁺ shows an increasing trend, BOD₅ in the middle and lower reaches shows an increasing trend; It is concluded that industrial pollution is the main driving factor of heavy metals As, Cr⁶⁺and Cd in Xiangjiang River trunk stream. NH₃-N in Yong Heng Zhu Tan, BOD₅, COD_Mn, TP in Hengyang and BOD₅ in Heng Zhu Tan are mainly affected by agricultural pollution; it is found that the industrial structure adjustment has a significant impact on the water environment, it is suggested to strengthen the transformation and upgrading in the process of industrial structure adjustment in the basin.