[Objective] In the background of global warming, the impact of climate changes on non-point source pollution load in Shaanxi section of Weihe River Basin was discussed in order to provide a basis for comprehensive river basin management measures, and the adverse effects of climate changes on water environment can be mitigated. [Methods] Based on the non-point source pollution distributed simulation model (SWAT model), the runoff and non-point source pollution loads in Shaanxi section of Weihe River Basin were simulated under the changes of climate factors such as temperature and rainfall in 2020, 2030 and 2050, respectively. The impacts of climate change on runoff and average annual loads of nitrogen(N) and phosphorus(P) in water were analyzed. [Results] ① Climate changes had a great influence on runoff in Weihe River Basin. The runoff increased with the future climate changes due to the increased temperature and precipitation. By 2050, in the case of the mean temperature increased by 2.2 ℃ and the rainfall increased by 7%, the runoff in the Weihe River will increased by 11.9%, which were comparing with the temperature, rainfall and runoff in 2012. ② Under the influence of the rising temperature and increasing in the future, the annual average total phosphorus load will increase. By 2050, in the case of the average temperature increased by 2.2 ℃ and the annual rainfall increased by 7%, the average annual nitrogen load in the basin increased by 20.9% and the total phosphorus load increased by 13.3%, which were comparing with 2012. [Conclusion] Under the future climate changes with the coefficient of rainfall increase and warming, the runoff of the river increased, and the total load of N and P in water environment increased, which will result in a rather serious problem of agricultural non-point source pollution.