Abstract: In this paper, a budget is computed for the vortex kinetic energy in the maritime main body (B) and continental ridgp (R) of the Subtropical High over the western Pacific in one of its ad-vance/feircat processes. Their contrasting analysis shows that the vortex kinetic energy in (B) mainly comes from the outer kinetic convergence. While in (R) it mostly depends on the conversion. With the High extending to the west and north to come under the South Asia High, (R) becomes more of thermodynamic one, resulting in insufficient vortex energy converted for the radiation loss and eventually the retreat of the subtropical high.