[Background]Studying the impact of human activities and precipitation changes on runoff and analyzing the main driving factors of the runoff changes in the upper reach of the Beiluo River basin could provide decision-making basis for water and soil conservation and rational use of water resources in the upper reaches of the Beiluo River basin and similar watersheds. [Methods]Based on the daily precipitation data and runoff data of Wuqi meteorological station in the upper reach of the Beiluo River basin from 1971 to 2014,the study uses the cumulative anomaly method,Mann-Kendall trend test,and precipitation-runoff double mass curve method to analyze the changes in trends and diagnosis the variation point of the annual precipitation and runoff changes in the upper reaches of the Beiluo River during 1971-2014. The double mass curve method and linear regression model are used to quantify the impact of climate change and human activities on precipitation and runoff changes in the annual scale and flood season. [Results]The results show that after the implementation of the Grain for Green Program in 2003, the precipitation-runoff relationship in the upper reach of the Beiluo River changed abruptly. The annual runoff and the flood season runoff after the mutation were significantly lower than those before the mutation,and the annual runoff changes were mainly caused by the reduction of the flood season runoff. Before 2003,the average daily runoff > 100 m~3 /s,> 1.15 m~3 /s,and < 0.5 m~3 /s were 0.27%,59.2%, and 8%,respectively,decreased to 0.07%,44.9%,and 0.048 after 2003. The contribution of human activities to the annual runoff and the reduction of runoff during the flood season was 106% and 114% respectively. The capacity of vegetation to regulate runoff is significantly increases a few years after the implementation of the Grain for Green Program due to the increase in the area of forest land and the reduction of farmland area. The number of the days that have extreme runoff has decreased obviously after 2003. The proportion of the non-flood season runoff accounts for annual runoff has decreased in recent years. At the same time,the ratio of moderate flow after the mutation increased compared to the previous years. Changes in runoff are less sensitive to changes in precipitation. [Conclusions]Large-scale of the vegetation restoration is a direct factor for the decrease of runoff in the Beiluo River's source area,and the policy of Grain for Green Program and soil and water conservation is the core driving force. At the same time,with the extension of the time for Grain for Green Program,the runoff in the upper reach of Beiluo River will not continue to decrease,and will remain at a relatively low and stable level in the future.