In terms of May～June 1991 SSTA over the eastern Atlantic and the three level global climatic model of Oregon State University, investigation is performed of the SSTA′s effects on the flood over the Jiang Huai valleys for June 1991 alongside the mechanism relating to the deluge in that area. It turns out that the positive SSTA in the midlatitude eastern Atlantic in connection with the negative at the tropical latitudes serves as one of the major factors responsible for the excessive rainfall.