To investigate the changes in digestive enzyme activities in the intestine and stomach, as well as the activities of non-specific immunoenzymes in the liver of juvenile Sebastiscus marmoratus under salinity stress, and to assess the ability of the juveniles to adapt to sudden changes in salinity, a salinity experiment was conducted. The experiment comprised four groups, representing different salinity gradient levels: 6, 8, 10, and 20 (control). These groups were referred to as S6, S8, S10, and S20, respectively. Results indicated that at the acute stress period of 96 hours, the activities of trypsin, pepsin, amylase, and lipase in S10 and S20 were significantly higher compared to those in S6 and S8 (P<0.05). Conversely, the activities of glutamic-pyruvic transaminase and glutamic-oxaloacetic transaminase were significantly higher in S6 and S8 compared to S10 and S20 (P<0.05). There was no significant difference in the activities of ACP and AKP between S6 and S8 (P>0.05). Additionally, the activities of ACP and AKP increased initially and then decreased over time in S10 and S20. These activities in S10 and S20 peaked at 12 hours, signifying a significant increase compared to other salinity levels. These findings suggest that the optimal salinity for breeding juvenile S.marmoratus ranges from 10 to 20.