In this study, we evaluated the effects of acute temperature and salinity change on the survival and immune function of Iwagaki oysters (). We measured the oysters' survival rates, superoxide dismutase (SOD), catalase (CAT), alkaline phosphatase (AKP), and lysozyme (LSZ) activities, and their malond­ialdehyde (MDA) content after they were transferred to environments with five different temperatures (15℃, 19℃, 23℃, 31℃, and 35℃) and six different salinity levels (16, 20, 24, 28, 36, and 40). In the temperature experiment, the minimum survival rate (34.44%) was observed at 35℃ and the survival rates of were higher in other treatments. At 15℃, the SOD, CAT, AKP, and LSZ activities were at low levels and the MDA content reached its highest value (46.93 nmol/mg pro). By contrast, the SOD, CAT, AKP, and LSZ activities and the MDA content in the treatment groups, reached their highest levels after acute temperature stress, then they decreased gradually to the control group level at 19℃, 23℃, and 31℃. In the salinity experiment, the minimum survival rate (71.11%) was observed at a salinity level of 40, which was significantly different from other treatments (<0.05). The 20, 24, 28, and 36-acute treatment salinity levels were suitable for the survival of The SOD, CAT, AKP, and LSZ activities were significantly lower than the control group (<0.05) and the MDA content reached its highest value (45.76 nmol/mg pro) on salinity level 16 for 144 h. The results demonstrated that acute changes in temperature and salinity had significant effects on the SOD, CAT, AKP, and LSZ activities as well as on the MDA content and survival rate of . Iwagaki oysters could adapt to seawater temperatures of 19℃, 23℃, and 31℃-acute treatment and 20, 24, 28, and 36-acute treatment salinity levels.