Abstract: In order to ensure rational utilization and to improve rainfall retrieval algorithms, it is of great significance to illustrate the characteristics and the sources of errors in the daily Tropical Rainfall Measuring Mission (TRMM) 3B42V6 precipitation product. In this study, we analyze the accuracy of three high resolution precipitation datasets at a spatial resolution of 0.25°×0.25° degrees using daily rain gauge data observed over the Ganjiang River basin. The three datasets are daily TRMM and other satellites precipitation product (3B42V6 derived), TRMM (3B42RTV6), and NOAA Climate Prediction Center Morphing Technique (CMORPH). Results show that the bias (B) of 3B42V6 is substantially less than that of 3B42RTV6 and CMORPH. However, CMORPH is more accurate than 3B42V6 as measured by other accuracy indices including the absolute bias (A_B), the Nash-Sutcliffe efficiency coefficient (C) and the probability of detection (P_D). The lower B values obtained from the TRMM 3B42V6 precipitation product are due to the fact that the rainfall monthly ground station data are used to correct the original TRMM data. However, the scheme for merging microwave and infrared (IR) precipitation information in TRMM 3B42V6 may not be as effective as the ones in 3B42RTV6 and CMORPH. As a result, the TRMM 3B42V6 precipitation product has higher A_B but lower C and P_D values compared to CMORPH. A further comprehensive assessment on the quality of daily TRMM 3B42V6 precipitation product is thus warranted to improve the performance of the scheme for merging microwave and IR precipitation information as well as the method of merging the satellite-gauge data.