In this study, 16 combinations of the ECMWF reanalyzed daily rainfall and the pentad CMAP in China for the period 1980～1993(1 May～31 Dec) were calculated. Correlation analysis was used to roughly evaluate daily rainfall for the whole of China and a combination of RPC (rotated principal component) and wavelet analyses were applied to data of observed and combined daily rainfall to obtain a detailed evaluation of the quality of these combined data sets in 6 selected major rainfall regions of eastern Asia in China. The results showed that except for intraweekly fluctuation the best combination was roughly similar to or accorded well with observation in the aspects of space variation patterns and long period rainfall fluctuations, related to monsoon onset and serious meteorologic disasters, indicating that this combination yielded better values of long term daily mean and standard deviation through the pentad CMAP, and can also represent rainfall fluctuations through the reanalyzed daily rainfall.