The 6hourly precipitation data from 673 rain gauge records are used to verify the accuracy of Tropical Rainfall Measuring Mission (TRMM) 3B42 products from June to August (JJA) during 2004-2008 in China. The results show that the satellite products are similar to rain gauge data in revealing the spatial patterns of JJA mean precipitation amount and precipitation frequency during 2004-2008. The pattern correlation coefficients of daily rainfall amount and rainfall frequency are 0.79 and 0.84, respectively. The satellite product overestimates rainfall frequency. Based on the spatial distributions of correlation coefficients of daily rainfall amount, the correlation coefficients between TRMM products and rain gauge data range from 0.6 to 0.9 in eastern China. According to the spatial patterns of mean absolute error (MAE) of daily and 6hourly precipitation amount, the MAE in South China is the largest, followed by the Yangtze River Basin. From diurnal cycle of the 6hourly total precipitation amount over eight subregions, the TRMM product has a good resemblance with rain gauge observations except the big difference in the afternoon (1400-2000 LST) in South China. Based on the spatial patterns of mean relative error (MRE) of different rainfall amount, the TRMM product behaves as follows: light rains is overestimated nearly in whole country; moderate rain is larger in some regions of eastern China; the MREs of heavy rain and torrential rain are less than 1 in most areas of China. Mean rates of the missing retrieval and the vacancy retrieval are 10% and 14% respectively in China.