Abstract: Using COADS in this paper, continuous changes of wind fields in the equa-torial Indian and Pacific Ocean are analysed. It is pointed out that changes of wind fields in the equatorial Indian and Pacific Ocean are contrary. During this El Nino west wind anomalies move gradually eastward from Indian Ocean to east Pacific. There are three anomalies of crossing-equator flows which associate with eastward moving west wind anomalies. Therefore, the interaction between both hemishpheres plays an important role in El Nino.