The high-resolution analysis on the carbon and oxygen isotopes and planktonic foraminifera of core SA12-19 dated with 14C approach in the Xisha Trough of South China Sea indicates that sediments are attributed to oxygen isotope stages 1-3 (stage 3 is not included completely), during the late-glacial to post-glacial periods. The sea surface temperature (SST) of each sample is calculated based on palaeoecological transfer functions (FP-12E). The results reveal a gradual thermocline increase in this area during oxygen isotope stages 1-3 e.g. a temporal thermocline deepening in the middle Holocene. During the Holocene, the SST was 23.3-27.2℃ in winter, 28.8-29.8℃ in summer. During oxygen isotope stage 2, the SST was 21.4-24.4℃ in winter, 28.1-29.0℃ in summer; and 21.9-25.2℃ in winter, 28.5-29.3℃ in summer during oxygen isotope stage 3. The SST in winter during oxygen isotope stage 2 was 2-6℃ lower than that of stage 3. During the transitional period, a "Younger Dryas Event", standing for a rapid climate return, occurred obviously.