The characteristics of the middle-high latitude circulation and the blocking high are analyzed. There were two blocking high in the middle-high latitude region of East Asia from the last ten days of June to the first ten days of July. This made the rainfall sustain in the Huaihe River Basin. In the last ten days of July, the blocking high in the Okhotsk Sea founded again and sustained in this place. So the subtropical high in western north Pacific region was in the south on an average, so the rain-belt did not advance northward and sustained mainly in the Huaihe River Basin.