Abstract: The outflow of mine water from coal mining may have an impact on the water quality of surface water systems.In order to study the present situation of surface water quality in Yushen Mining Area, five groups of surface water samples along the Tuwei River and Yuxi River were collected on July 2015.The hydrochemical characteristics of surface water were analyzed by mathematical statistics.Piper three-line analysis was used to analyze the hydro-chemical types of surface water and the main ion composition characteristics.The sources of major ions in surface water and their influencing factors were discussed by Gibbs diagram and ion correlation method.The results show that the TDS of the Tuwei River in the study area ranged from 404.32 to 794.17 mg/L, with an average of 529.68 mg/L, and the TDS of Yuxi River was from 303.73 to 434.77 mg/L, with an average of 356.88 mg/L, all of which were weak bases.The surface water cations were dominated by Ca2+ and Na+.The average concentrations of Ca2+ and Na+ in the Tuwei River were 63.33 and 46.63 mg/L respectively.The average concentrations of Ca2+ and Na+ in the Yunxi River were 61.08 and 16.44 mg/L respectively.Anions were mainly width=753,height=49,dpi=110 chemical parameters of surface water in the Tuwei River surface gradually decreased from upstream to downstream, while those in Yuxi River increased gradually from upstream to downstream.According to the correlation matrix of various chemical indexes in surface water, there was a significant positive correlation between TDS and K+,Na+,Mg2+, width=589,height=23,dpi=110 was significantly correlated with K+, Na+and Ca2+ respectively, suggesting that these ions may be derived from the same substance and may be derived from the dissolution of sodium-containing silicates.The main ions in surface water were mainly derived from weathering and dissolution of silicate rocks and cation exchange.The concentrations of width=73,height=23,dpi=110 and Cl- in surface water were locally higher, but most of them were lower.This indicate that the local area of surface water was slightly affected by human activities, but the impact of human activities on surface water quality was limited due to the effects of river runoff, mixing and dilution.