Abstarct: Rainfall is one of the complex and vital elements of the atmosphere, which plays an important role in the feeding of seas, rivers and groundwater . Therefore , accurate estimation of rainfall is important in the prediction of heavy rainfall hazards, the estimation of groundwater recharge and water supply to maintain environmental conditions . In this study the performance of TRMM -۳ B۴۳ V۷ satellite in estimating of rainfall on monthly, seasonal and annual scale were evaluated. For this purpose, rainfall measured data in ۲۹ synoptic stations in IRAN were used in the period of ۱۹۹۸- ۲۰۱۶. The performance of the TRMM satellite in estimating the rainfall using index indices (R^۲), Nash - sutcliffe (NSE) and the root mean square error (RMSE) were evaluated .The results showed the highest error of TRMM satellite on monthly, seasonal and annual scale in stations Illam, Shiraz, Qom, Ardebil and Rasht ( RMSE between ۱۸.۰۱ to ۷۴.۸۰) and minimum error in stations Mashhad, Kerman, Zahedan and Ahvaz (RMSE between ۰.۱۳ till ۷.۴). The highest amount of determining factor in the time scale is related to the stations Yasuj, Ahvaz, Shiraz and Birjand and to range ۰.۸۸ till ۰.۹۹ has been variable. The low and high error of rainfall estimation were related to wet and humid climate and semiarid climate, respectively. The rainfall changes trend of stations investigated by two methods of, Theil Sen (TSA) and Pre-white without trend (TFPW). In the monthly, seasonal and annual time series, it showed that the most negative changes related to the Qom station with statistic Z = -۲.۵۸ in april and the annual scale, the most negative trend was related to Qom station with statistic Z = -۲.۶۵ In the seasonal scale, the Yasuj station in winter has the highest negative trend between stations with Z =-۴.۴۰ .