Abstract: The paper calculated and analyses the onset time of South China Sea Summer Monsoon during 1949 to 2009,and discussed anomalies of the General Circulation in the early and later years used the NCEP daily reanalysis data.The results showed:1) a sudden increase in precipitation in the South China Sea Summer Monsoon onset,and the onset time becomes earlier during 1949 to 2009.2) For the anomalies of early years and late years,in 200 and 500hPa,the Tibetan Plateau and the Southwest Pacific has abnormal stronger westerly,Bay of Bengal and the South China Sea has abnormal weaker easterly.3) For the anomalies of early years and late years,in 850hPa,the Bay of Bengal,the South China Sea and East China Sea has abnormal stronger westerly winds,Southwest Pacific has abnormal weaker easterly.And the northern Tibetan Plateau has abnormal weaker northerly wind,the east China,the South China Sea and the Bay of Bengal have abnormal weaker southerly,and Tokai has abnormal stronger southerly.