Abstract: The boundary between east wind and west wind (WEB) was definded as the dynamical parameter of describing subtropical high ridge location.Based on NCEP/NCA Rreanalysis monthly mean data the spatial and temporal variation charact eristrics of WEB were investigated.The results show that the seasonal variation of WEB,consisting of the movement of latitude location from south to north or from north to south and its slope change,is the main part in the movement of the subtropical high ridge.The annual variation of subtropical high ridge is associated with ENSO intimately.The subtropical high in the Southern Hemisphere is longitudinally symmetric vertical structure,but in the Northern Hemisphere,its vertical structure is more complex.The west Pacific subtropical high ridge presents unique feature in the global subtropical high ridge system.