In terms of the NCEP/NCAR daily-mean reanalysis data (1975－2005), it is found that the upper troposphere anti-cyclone to the east of the Philippines break into two portions, the west anticyclone is above the Indo-China Peninsula (ICP) while the east one still stays above the ocean to the east of the Philippines. The South Asia high (SAH) forms by the reinforcement of the west anticyclone. The formation and strengthening of the ICP upper anticyclone and the weakening and vanishment of the anticyclone above the ocean to the east of the Philippines occur simultaneously, which composes the chief characteristics of the SAH establishment processes above the ICP from April to May, while the primary impact factor of the processes is the variation of the diabatic heating condition on the south of the Asian continent. With the northward propagation of the convection along the Asian－Australian “Land Bridge” and the buildup of the ICP convection, the upward motion over the ICP and the upper troposphere divergence strengthen, so that west center forms and the SAH establishes initially. Whereafter the heat source which has been on the ocean to the east of the Philippines withdraws eastward to the east of 150°E suddenly, the ICP heat source becomes the leader, which stimulates a cyclonic circulation to the east of the heating zone in the upper troposphere that results in the abruption of the SAH near 120°E. Then because of the strengthen of the BOB-ICP convection and the establishment of the BOB-ICP summer monsoon (BOB is short for Bay of Bengal), a great deal of latent heat is released above the ICP, which makes the vertical motion enhance so that the west center intensifies and moves northward. The South China Sea (SCS) convection begins strengthening at the same time, and the released latent heating can stimulate the upper-level positive vorticity variety, which makes the east center weaken and disappear, and the SAH establishes completely above the ICP.