Abstract: In the paper, It had been pointed out that the main difference between Indian and East Asian summer monso on is the circulation of mid-high latitude had great influence on East Asian Summer monsoon. The study showed that during the flood years, the center of positive anomaly is around Okhot sksea, the negative center is around the mid-latitude and the another center of positive anomaly is around low-latitude over East-Asia, the positive and negative ano maly centers at 500 hPa level for med the anomaly wave train from low latitude to high latitude overeast Asia, At the same time there is another anomaly wave train from Ural mountains to Okhotsk sea in mid-high latitude, the positive anomaly center is around Uralmountains, the negative center is around Lake Baikal, the another positive center is around Okhot sksea. There is almost opposite wave train arrangement between flood and drought case of Changjiang river basin over Mid-high latitude and East Asia. The correlation between Okhot sksea and North Hemisphere had been made based on 500 hPa height data during 1951～1994 years. The status of Okhot sksea played anim-portant role in the forming of opposite wave trains for flood and drought case in Changjiang river basin. So, the pat terns of anomaly wave trains closely related to the status of Okhot sksea. Astrong persistent anticy clone remained over the Okhot sksea at 500 hPa level of ten causes summer flood events in Chang jiang river basin.