Abstract: The relationship between the summer monsoon intensity in East Asia, defined as the difference of sea level pressure from 110°E to 150°E, 10°-50°N, and the rainfall distribution over China is examined. It is foundthat the rainfall distribution over China varys with the variation of summermonsoon intensity. Meanwhile this analysis shows that the planetary scale circulation is also modified accompanying the variation of summer monsoon intensity. Finally, the possible cause of variation of summer monsoon intensity is discussed.