The effects of storage temperature on post-mortem changes in the muscle of chub mackerel caught in winter and in summer were investigated. The rate of progress of rigor-mortis was slowest in the group stored at 5°C in both experiments in winter and in summer. The changing rates of concentrations of ATP, IMP, inosine,and creatine phosphate of the dorsal muscle were slowest in the 5°C group in the winter experiment. In the summer experiment, those in the 5°C and 10°C the groups were slower than those in the 0°C group. The changing rate of the K-value in the 10°C group was more rapid. The values of breaking strength of dorsal muscle in the 5°C group were maintained significantly high values in winter, and slightly in summer. From these results, it was considered that the desirable storage temperature for delaying post-mortem changes of chub mackerel was 5°C regardless catch seasons.