Abstract: Through analysing the maps of monthly mean satellite cloudiness, the major characteristics of ITCZ over the Pacific Ocean have been revealed in this paper. Both the location and the intensity of ITCZ over Western Pacific exhibit significant seasonal variation, showing double ITCZ in northern summer While the ITCZ over Eastern Pacific is located steadly at about 5°-8°N with very little seasonal variation. These differences may be related to the distribution of thermal condition in the tropical Pacific.In addition, the ITCZ over Western Pacific shows also the interannual variation obviously, which influences to a certain extent the typhoon’s activities in this region.