[Objective] To verify and use TRMM(tropical rainfall measuring mission) 3B43 precipitation product in the Heihe river basin(HRB) in order to understand the spatial distribution of precipitation and provide reliable data for hydrological and ecological studies.[Methods] The TRMM 3B43 V7 precipitation data and 11 meteorological data in HRB was collected from 1998 to 2013. The indices including CC(correlation coefficient), RMSE(root-mean-square error), ME(mean error) and MAE(mean absolute error) were used to assess the accuracy of TRMM data within the basin, and the spatial distribution characteristics of each index was investigated.[Results] It showed that there was an extremely significant correlation between TRMM and the observed data, but the TRMM data might be a little bit overestimated, monthly average rainfall could be overestimated by 2.84 mm, and seasonal and annual value could be overestimated by 34.1 and 8.55 mm, respectively. The value of CC and RMSE decreased from upstream to downstream, the ME value in upstream was far lower than in the middle and lower reaches at all three scales. The value of MAE was the lowest in upstream, but it is highest in the middle reaches at the annual scale, and a similar trend was found at the seasonal scale. The MAE value decreased from upstream to downstream at the monthly scale.[Conclusion] According to the TRMM data, the distribution of the annual average rainfall decreased from the southwest to north and central part of the basin. The precipitation gradient distributed showed as upstream > midstream > downstream. The annual precipitation distributed unevenly, mainly concentrated in the period from May to September.