Based on the mass stream function scheme and EOF(empirical orthogonal function),the NCEP／NCAR reanalysis data were used to investigate the meridional circulation changes and their relations with SSTA(sea surface temperature anomaly) form 1979 to 2006.The conclusions are as follows:(1)The south Hadley cell emerges together with the boreal Hadley cell which is more intensive over 105—125°E in boreal summer.These two meridional circulations are named as the “Hadley cell pair”;(2)During the past 28 years,this pair of Hadley cells varies with periodicities of 2—4 and 4—6 years.The south Hadley cell tends to move southward while the intensity of boreal Hadley cell tends to stronger,especially before the mid 1990s;(3)Variations of Hadley cell pair is significantly correlated with IOD (Indian Ocean Dipole) and ENSO events.Lag and simultaneous correlations of the leading EOF mode for Hadley cells with SSTA is consistent with the SST pattern of El Nino developing or prevailing period over the Pacific.That the south Hadley cell is northward (southward) and that the boreal Hadley cell is weak (severe) are correlated with the development of El Nino(La Nina) in the coming winter.This can be a potential indicator in predicting ENSO events.The IOD SSTA is able to change the south Hadley cell.With negative IOD events,the south Hadley cell is weakened.However,with positive IOD events,there is no obvious opposite phenomenon.