Abstract: A global spectral atmospheric general circulation model of 15 wavenumbers in horizontal rhomboidal trunction and 9 vertical levels is used to simulate the responses of the atmosphere to the SSTA of the tropical seas in July. Ten anomaly runs and one control run are designed to study the influence of SSTA of the Arabian Sea, Bay of Bengal, South China Sea and the Western Pacific Ocean in various collocation on the global atmospheric circulation, especially on the Asian monsoon circulation. The result shows that the thermal condition of the tropical seas is an important factor in affecting the variability of the Asian monsoon circulation and precipitation.