Abstract: In this paper, El Nino phenomenon occurred along the western coast of South America (1971-80) and the influence of it on the summer monsoon circulation over East Asia were analysed. The results show that the major El Nino years were in the years 1972 and 1976, while the pronounced anti -El Nino years were in 1971 and 1974. It is also pointed out that there was a negative correlation between El Nino and the summer monsoon over most part of East China in July.The major circulation characteristics in El Nino years are as follows; (1)The position of the western Pacific subtropical high lies to the north of its normal position and its intensity is week. (2)The position of the Australia high lies rather in south. (3) The equatorial buffer ridge is strong. The northern ITCZ extends eastward to the middle of the Pacific. After the south hemispheric trade crosses the equator near 105° E,it will turn eastward near 10°N and run onto the western Pacific.(4)The monsoon breaks over India subcontinent.The SW monsoon component from the Bay of Bengal which affects directly the east areas of China is very limited. The characteristics of each system as mentioned above in anti- El Nino years are quite different from that is El Nino years.When El Nino phenomenon took place, it results in the fluctuation of the summer monsoon circulation system,and at last exerts an influence on the intensity of the summer monsoon over East China. It is thought that this is a possible process of the teleconnexion between the El Nino, phenomenon and the summer monsoon.