Abstract: The seasonal meridian-shift of South Asia High Ridge Line is investigated by means of a zonal average model,which is subjected to the assumption of a geostrophically balanced zonal wind. The dynamic influences and the role of heat source connected with the topographys are discussed through the z-σ coordinates. The sea surface heating on the bay of Bangal and the condensation heating above there are also studied.As a consequence, the simulating zonal circulations which are in rather good agreement with the actual situations above Tibetian Plateau in summer are obtained, and some interesting conclusions about meridional Shift of South Asia High Ridge Line are given.