The juvenile Hexagrammos otakii was artificially bred as the research object.The effects of different photoperiods on the growth, lipid metabolism and antioxidant enzyme activity of Hexagrammos otakii were studied through an 8-week culture experiment with five photoperiod experimental groups of 24L∶0D, 16L∶8D, 12L∶12D, 8L∶16D and 0L∶24D. The results showed that except 0L∶24D, the juvenile Hexagrammos otakii survived well in experimental condition, and the survival rate was more than 95%. The average body mass growth rate, average body length growth rate and bait conversion rate reached the maximum under 12L∶12D photoperiod, and there was no significant difference compared to the 16L∶8D treatment group (P＞0.05). Except for triglyceride, the activities of other metabolic enzymes were higher under 12L∶12D and 16L∶ 8D photoperiods, but the difference was not significant(P＞0.05). With the extension of illumination time, the activities of superoxide dismutase, catalase, malondialdehyde decreased first and then increased, and reached the lowest value under 12L∶12D photoperiod, and there was no significant difference compared to 16L∶ 8D treatment group (P＞0.05). In conclusion, the photoperiod suitable for the growth of juvenile Hexagrammos otakii is 12L∶12D and 16L∶8D.[Chinese Fishery Quality and Standards,2023,13(5):10-16]