Abstract: As high temperature stress due to climate change threatens coral reefs in the tropics, cooler, relatively high latitudes may become potential refuges for corals. Tolerance to low temperatures is critical in determining whether corals can successfully migrate to relatively high latitude refuges. However, the tolerance capacity and physiological adaptation mechanisms of corals to low temperature stress are unclear. In this paper, Porites lutea populations were studied at three latitudes in the South China Sea, including Xisha Islands（XS）, Weizhou Island（WZ）, and Daya Bay（DY）. The ambient temperature was lowered from a gradient of 26 ℃ to 12 ℃ during an 18 d experimental cycle. The physiological phenotypes and enzyme activity data were obtained by low temperature stress to compare the ability of P. lutea to tolerate low temperatures in different seas. The results showed that the three groups of P. lutea had similar response patterns to low temperature stress, all of which exhibited contraction of coral tentacles, marked increase in coral bleaching, and significant decrease in Symbiodiniaceae density, maximum quantum yield（Fv/Fm） and chlorophyll a content. The activities of anti-oxidants（catalase, total superoxide dismutase, reductive glutathione） contributed to understanding the degree of oxidative stress in corals. The trend of the enzyme activities remained consistent during the cooling process, with all significantly increasing and then decreasing. The higher tolerance of P. lutea to low temperatures in Daya Bay and Weizhou Island compared to Xisha Islands may be an indication of long-term adaptation to large temperature changes in relatively high-latitude populations. This study will provide a theoretical basis and guiding suggestions for the program design of artificially assisted coral migration, and provide physiological data for the low-temperature adaptation of corals.