The multiscale characteristics and period of summer precipitation in the Changjiang-Huaihe River valley have been analyzed by using the wavelet transformation.Through the wavelet transformation of Nino3 SSTA,indices of west Pacific subtropic high and Asian zonal circulation,the multiscale associations between them and rainfall in the Changjiang-Huaihe River valley have been investigated.The results suggest that precipitation of the Changjiang-Huaihe River valley has obvious interannual and interdecadal variation characters.The interannual peorids are found in 2～3, 5～6 and 7～8 year. The interdecadal periods are found in 12～13, 16～17 and 27 year.The characters of the south and north regions,as well as those of the middle and lower reaches of the Changjiang River,are different.The impact of Nino3 SSTA on rainfall in the Changjiang-Huaihe River valley is more significant than the impact of Asian zonal circulation.The association of the Nino3 SSTA,as well as the indices of western Pacific subtropic high,with rainfall in the Changjiang-Huaihe River valley is in-phase in some periods,but out-of-phase in other periods.