In this study,the accuracies of the final products of Integrated Multi-satellite Retrievals for Global Precipitation Measurement(GPM)(IMERG),from September 2014 to August 2015 over mainland China(MLC),are evaluated through the quantitative and classification scoring methods using the China Gauge-Based Daily Precipitation Analysis(CGDPA) products,developed by the National Meteorological Information Center.The results are as follows:1)The IMERG can display the spatial distribution characteristics of the precipitation over MLC with relatively high accuracy,although the accuracy is lower than that obtained by the CGDPA over some areas.The spatial distribution of the IMERG seasonally averaged precipitation has a rather high consistency with that obtained by the CGDPA,especially over the central,eastern and southern parts of MLC.2)The correlation coefficients retrieved by the daily precipitation of the IMERG and CGDPA range between 0.2 and 0.5 over most areas of MLC,except for a small number of areas where they exceed 0.6,and are even negative over some areas.3)Although the accuracies of the IMERG over eastern part of MLC are significantly higher than those over the west,the daily precipitation estimation of the IMERG is as much as 10%-30% lower than the daily precipitation of the CGDPA over the east.4)The largest difference of the probability density between the IMERG and CGDPA is small-amount precipitation,followed by moderate rain,while the differences between the two in the other precipitation intensities are very minor.5)None of probabilities of detections(PODs) of precipitation events for the IMERG in any of the four seasons are significantly high,while the false alarm ratios(FARs) are relatively high.In addition,the critical success indexes(CSIs) are relatively low.