In order to elucidate the variation rule of rainfall erosivity (R) in Huangfuchuan Watershed, R value was estimated from 1954 to 2004 based on the daily rainfall data of 15 precipitation stations in Huangfuchuan Watershed, and the spatial and temporal variation of R was analyzed by Mann Kendall nonparametric tests and Kriging space interpolation method. The results are shown as follows. 1) The characteristics of spatial and temporal variation of R value were generally consistent with those of total rainfall and erosive rainfall; spatially, R value decreased and the contour lines of R value thinned from southeast to northwest. 2) From the temporal point of view, R value was concentrated from May to September, R value during this period accounted for more than 96% of the total annual R value; especially from July and August, R value amounted to 72.4% of the total annual R value. 3) Annual R value at nine stations had an increasing trend, but only at two stations such trend was significant over 51 years, while it had a deceasing trend at the other six stations and also only at two stations this decreasing trend was significant over 51 years. For the whole Huangfuchuan Watershed, the change of R value was consistent with the variation of rainfall and erosive rainfall, and showed an insignificant trend of decreasing over 51 years.