The recorded runoff of the Xinshui River has experienced significant declining trend during the past decades,which has taken a huge challenge to local ecological environment restoration and utilization of water resources.Runoff series was naturalized by using hydrological simulation approach,impacts of climate change and human activities,including soil and water conservation measures implementation,were then analyzed.Results show that SWBM model performs well for monthly discharge simulation,Nash-Sutcliffe coefficients for calibration and verification periods are both above 70%,while relative errors are less than 5%.The recorded abrupt change of runoff series has occurred since 1966.Runoff depth over the basin in 1966-2010 reduced by 29.2 mm as compared to that in previous period,in which human activities contributed 49.3% of total runoff reduction,while climate change contributed to 50.7%.Therefore,impact of climate change on hydrology and water resources of the Xinshui River basin should be attracted sufficient attention with respect to soil and water conservation and ecological civilization construction.