Based on the precipitation data from 35 rain gauge stations of the southern Shandong Province and using the quantitative and classification score methods, the authors evaluate the applicability of GPM/IMERG products from time, space and rainfall intensity from January to December 2016. The results show that the IMERG data has high precision in the southern Shandong Province as a whole. The correlation coefficient between IMERG and site observation data is 0.8, the root mean square error is 5.47 mm/day, and the relative deviation is 2.27%. In terms of time, the IMERG data is consistent with the overall trend of average daily precipitation and monthly precipitation in the observation area of the site. The accuracy of the IMERG data in summer is better than those in other seasons. From a spatial point of view, the IMERG data will be underestimated in the areas with more annual precipitation, and overestimated in the areas with less annual precipitation. The IMERG data are more accurate in the midlatitude mountains and hill areas than those in plain in estimating. The estimation accuracy of IMERG products is related to rainfall intensity. When the precipitation level is microprecipitation (less than 1 mm/d), the IMERG estimation ability is weak. When the precipitation intensity is light rain and above, the difference between IMERG product and actual observed probability density is small. IMERG has a strong ability to estimate stable precipitation. In the months of more precipitation, the detection accuracy of IMERG is higher, the false alarm ratio is lower, and the critical success index is better.