Abstract: The data show that the temperature anomaly core of vertical Maximal Sea Temperat ure Anomaly (MSTA) level moves eastward from “warm pool” in Equatorial Western Pacific Ocean to 95°W in Equatorial Eastern Pacific Ocean and turns to northwa rd and southward to 10°N,10°S respectively and then turns to westward to 140°E and returns to “warm pool” in Equatorial Western Pacific Ocean. They make up a pairs of cycles. The north cycle is stronger than the south one. This study focu s on the possible mechanism of the temperature anomaly core turning westward near eastern Pacific Ocean 10°N, 10°S. The wind fields in 850 hPa show that there is meridian wind near eastern Pacific Ocean coast when ENSO growing (fizzling). It rouses Kelvin wave and upwelling (down welling) along the coast. The Rossby wav e s of west propagating in various latitudes are triggered by upwelling (down welling) along the coast. The theoretic analysis shows that the upwelling (down welling) and Kelvin wave along the coast triggered by periodic meridian wind which is similar to the observation are biggest about 10°N, 10°S. So the amplitude of the Rossby wave reaches maximum at that location. It makes the anomaly cool (war m) water easily transport to western Pacific Ocean.