Abstract: A statistic study of frontal cyclones over East Asia and north-western Pacific for the period 1958-1989 is carried out by using the historical weather maps,compiled by State Meteorological Centre.There are two major cyclogenesis areas including the Mongol cyclogenesis area, in which the great frequbacy occurred, and the East Asia coastal cyclogenesis area.All of those areas appeared a pronounce seasonal variation.The seasonal variation.The seasonal variation of explosive cyclones are also discussed.Finally, the main cyclone tracks are determined by the relative variation of cyclones.