Abstract: Observed data in a survey in 1984-1986 of solar radiation is analysed for tropical western Pacific and South China Sea. It is shown that total radiation for the same marine region differs in amount significantly with season and we ather situation. The maximum occurs when the region is within the central area of the subtropical high while the minimum is observed if it is influenced by a surge of the southwestly monsoon. The total radiation is always greater on the southern edge of the subtropical high than in the center of it,due to the close radiative association with the variation in total cloudness in daytime.