Abstract: The analysis and objective regionalization of SST field in the South China Sea are set up using the orthogonally rotated factor analysis based on maximum variance criteria.The result shows that the whole South China Sea SST field may be divided into seven regions having different changing rules respectively.They reflect different characteristics of oceanic dynamics and are related with monsoon, ocean current, vortex and geographical features, respectively.Furthermore, from the maximum entropy spectra and cross spectra of the factors' time series, significant periods in SST oscillations for individual regions and marked coupling oscillation periods among them are derivde.The result shows that each region has specific property and is correlated with each other.