In terms of EOF analysis,the variability of the oceanic subsurface temperature,divergence,zonal current velocity,and surface zonal wind stress on the vertical cross-section along the equator(0°) in the tropical Pacific Ocean and their relations are discussed.Results show that the first two EOF modes represent the dominant component of the above physical quantity fields,with the second mode ahead 8 months of the first mode.The first two and fourth physical quantity fields mentioned above varied almost synchronistically,3-4 months ahead of the variation of zonal current.So it is deduced that when there exists zonal westerly(easterly) wind stress anomaly over the tropical Pacific Ocean,the upper water mass convergences(divergences) and the lower water mass divergences(convergences) results in the anomalous downwelling(upwelling) of water mass,which leads to an increase(decrease) of subsurface sea temperature and a westward(eastward) velocity anomaly of zonal current.