Abstract: Based on SVD (singular value decomposition), CSVD(combined SVD) used to examine the correlation of a vector field and a scal ar field is developed in this paper. With CSVD, the effects of ENSO on the Asian summer monso on cir culation and the summer precipitation in China are examined. The results show that, in an El Nino year, the Indian summer monsoon is subsided, the eastern Asian summer monso on is st rengt hened. On the contrary, in a La Nina year, the Indian summer monsoon is enhanced while the eastern A sian summer monsoon is abated. The areas mostinfl uenced by the tropical middle-east Pacific SST Amainly lies on the Yangtze rivervaley the converging area of the north and the southair stream and the Somalia jetarea. And the most significantly affected area of ENSO to the summer precipitation in China is the Yangtze and the Huaihe river valley.