Abstract: The paper studies the formation and development of extratropical cyclone occurred in Shandong adjacent waters from 1958—2004,such as multiple months,moving path,generating sources,cyclone intensity,and occurred frequency in interannual variability Circulation of 500hPaheight.The results show that the extratropical cyclone effects on Shandong adjacent waters appeared more in June,July,Augest,for summer,accounting for 51% of the total year-round.In addition to Jianghuai cyclone and Huanghuai cyclone,the disturbance of quasi-stationary front on sea surface is also formation and evolution of factor to extratropical cyclone.