Abstract: Based on the daily rainfall data of May-to-August from 1954 to 1983, this paper analyzes the climatic characteristics of precipitation in East China and discusses their association with seasonal variations of the East Asian monsoon.It is found from the analysis that both the Jianghuai (the Yangtze and Huaihe river basins) mei-yu and South China summer monsoon rain have seasonal interlock characteristics; the former shows a single peak dustribution while the latter displays a double peak distribution. Meanwhile, the intraseasonal variations of precipitation in both areas show a periodic oscillation of 15-25 days. The peak value of precipitation in the Yangtze and Huaihe river basins and the first peak value in South China are mainly affected by the subtropical monsoon,i.e.they are associated with the seasonal northward advancnig and strengthening of the summer monsoon. The second peak value of precipitation in South China is influenced by the South China sea tropical monsoon and closely related with the tropical cyclone activities in the corresponding period.