Using the precipitation data given by high-density regional automated weather stations during main flood season in Hunan Province, in 2013, Cressman algorithm is introduced to calculate the regional precipitation value in 0.01?×0.01?resolution and is compared with the methods of a reciprocal of distance square, distance exponent, and distance square exponent. It is shown that the precipitation construction of Cressman algorithm is finer and closer to the features of gage data than other methods. Precipitati...