[Objective] To study the temporal variability and spatial distribution of rainfall erosivity in Weihe River basin in order to provide a reference for soil and water conservation.[Methods] Based on the daily rainfall data from 1957 to 2014 in 30 meteorological stations in Weihe River basin, the rainfall erosivity model proposed by Zhang Wenbo was used to calculate the rainfall erosivity, and its temporal variability and spatial distribution were analyzed.[Results] The range of annual rainfall erosivity in Weihe River basin was 806~4 017.81 MJ·mm/(hm²·h) with an average value of 1 798.97 MJ·mm/(hm²·h). The average annual erosivity decreased from the northwest to the southeast in general. There was strong correlation between the average annual erosive rainfall and the rainfall erosivity, and they had similar spatial distribution. The rainfall erosivity from July to September account for 63.91% of the total annual rainfall erosivity, showing an unimodal annual variation. Soil water loss was found mainly concentrated from July to September in the northern of the Loess Plateau and Guanzhong region. Great soil erosion might potentially occurred from May to October in Qinling Mountains. The risk of erosion increased from the northwest to the southeast; The inter-annual change of rainfall erosivity in Weihe River basin was obvious with the C_v value ranging from 34% to 56%. C_v value of rainfall erosivity in northwest region was larger than that in southeast region in general. The annual rainfall erosivity of most areas in Weihe River basin showed upward trend with different rates, except for the decline trends of Luochuan, Changwu,Huanxian and Pingliang stations.[Conclusion] There were significant differences of rainfall erosivity in spatial and temporal distribution. Although rainfall erosivity in Weihe River basin showed a decreasing trend, soil and water conservation work is still very important.