Abstract: This paper documents the correlationship between sea surface temperature(SST) and sea level wind(SLW) in the South China Sea(SCS) based on COADS(1958-1987).Further statistical analysis shows that there is a fixed SCS basin mode for both ST and low level wind(such as SLW,1000hPa and 850hPa winds)in the region on the terannual time scales due to air-sea interaction. A simple coupled model including the feedback between the upper layer in the SCS and the circulation of East Asian monsoon demonstrates an interannual oscillation in the oupled air-sea system,which is similar with the observations in the SCS.