Abstract: By comparing the individual growth indicators of Takifugu obscurus juveniles during freshwater cultured and seawater cultured, the activities of digestive enzymes and non-specific immune enzymes, and muscle biochemical components were determined to explore the effects of freshwater culture on growth and physiology of T.obscurus juveniles. The results showed that the body length and body mass growth of T.obscurus juveniles in the freshwater groups and seawater groups were significantly affected by the salinity, and the growth indexes of the juveniles in freshwater group were better than those in the seawater group (P<0.01). The activity of Na⁺/K⁺-ATPase was significantly lower than that of the seawater group, and the LZM activity was significantly higher than that of the seawater group (P<0.05). There were no significant differences in the activities of antioxidant enzymes, digestive enzymes and muscle biochemical components between the freshwater groups and seawater groups (P>0.05). Compared with seawater culture, freshwater culture was more conducive to the growth of T.obscurus. This study could provide scientific data for T.obscurus large-scale healthy farming.