L9R15 climate spectrum model is employed to investigate the effect of summer SSTA in the equatorial Indian Oecan and Pacific on Asian summer monsoon.It's found that the positive SSTA in summer in the tropical Indian Ocean or Pacific can,not only cause the response of atmospheric circulation and precipitation in the tropical region,but also lead to the weakening of east Asia and south Asia summer monsoons.However,the output with SSTA imposed in two waters together is not a linear sum of the output with SSTA imposed individually in two waters.As such, the schematic map is proposed to demonstrate the simultaneous relationship between the Asian summer monsoon and the atmosphere-ocean system in the tropical Indian Ocean and Pacific.