Abstract: This paper provides a method for merging precipitation observation data with satellite remote sensing data to supplement the precipitation contour map with the North Korea side of the Yalu River, a region lacking the meteorological and hydrological data, focusing on estimation of the probable maximum precipitation (PMP) in the basin above Yunfeng dam. An enlargement method and a transposition method are used separately to calculate this PMP. The three-day PMP estimated by the enlargement method is 256.5 mm, while its estimation by the transposition method is 203.2 mm. By detailed comparison, the former estimation is recommended by this study. This estimation is reasonable and reliable if it is compared with the historical precipitation data in this basin and previous studies on the PMP in China. The results would help estimate PMP for ungauged regions.