Abstract: Based on the ground-observed hourly precipitation data and the China multisource precipitation analysis (CMPA) product developed by the National Meteorological Information Center, the areal rainfall of the Haihe River basin from June to September 2021 is estimated using the arithmetic mean method. We objectively and quantitatively evaluated the applicability of the CMPA product with a resolution of 5 km in the Haihe River basin using multiple evaluation indicators, such as the correlation coefficient, average error, and root-mean-square error. The results show that the CMPA product is consistent with the ground observation data, reproducing better spatial and temporal variation characteristics of the areal rainfall in the Haihe River basin from June to September 2021. Compared with the ground observation, the CMPA product overestimated the areal rainfall of the Haihe River basin, and the larger the precipitation, the larger the error observed in the CMPA. By comparison, errors observed between the ground observation and CMPA product are closely related to the average precipitation amount, altitude, and area of the sub-basin. In terms of the areal rainfall frequency at individual magnitudes, the CMPA product is close to the ground observation, with an accuracy of over 90%. In short, the quality of the CMPA product is high; therefore, it can be applied to meteorological operations for the areal rainfall refinement in the Haihe River basin.