Abstract: Subtracting main information from periodicity analyses,relationship among sea surface temperature over the equatorial Pacific Ocean (SSTep),meridional index for the westerly circulation over Europe-Asia (Mlea),area index for the subtropical high over the West Pacific (AIwp),and rainfall in Guangzhou (Rg) are investigated in the paper. They interact so closely that the Mlea fluctuates prior to SSTep,which again prior to AIwp,which yet again prior to Rg. There is also evidence for prior changes in AIwp to those in MIea.Furthermore.the role of Mlea in El Nino processes,which may contribute to a quasi-2-year oscillation popular for low latitudes,is comfirmed. Finally,the possibility is shown for predicting El Nino and coastal precipitation for South China using the variations of circulation and SST.