To investigate the effects of dietary supplementation with varying levels of sodium butyrate(SB) on growth performance, hepatic immune and antioxidant capacity, and the expression of appetite-regulating genes in juvenile Sebastes schlegelii(33.56±0.08g), six isonitrogenous and isolipidic experimental diets were formulated by adding0(D1), 0.5g/kg(D2), 1g/kg(D3), 2g/kg(D4), 4g/kg(D5)or 8g/kg(D6) of coated sodium butyrate to a basal diet. Each diet was fed to triplicate groups of fish for 60 days. The results demonstrated that weight gain rate (WG), specific growth rate (SGR), and feeding rate (FI) initially increased and then decreased with increasing SB levels, peaking in the D4 group (P<0.05), while the feed conversion ratio (FCR) significantly increased in the D6 group (P<0.05).? Dietary SB significantly upregulated the relative mRNA expression levels of hepatic growth hormone(gh) and insulin-like growth factor-I(igf-I). The activities of hepatic superoxide dismutase(SOD), catalase (CAT), and alkaline phosphatase(AKP) initially increased and then decreased, reaching their highest levels in the D4 group (P<0.05). Hepatic alanine aminotransferase (ALT) and aspartate aminotransferase(AST) activities followed a similar trend. Intestinal interleukin-1β(il-1β) and interleukin-8 (il-8) mRNA expression levels initially decreased and then increased, with D4 and D5 groups being significantly lower than D1 (P<0.05). Conversely, transforming growth factor-β(tgf-β) mRNA expression initially increased and then decreased, peaking in the D5 group. Compared to the control group(D1), long-term SB feeding in the highest-performing group (D4) significantly reduced hepatic leptin (lep) and cerebral leptin receptor (lepr) mRNA expression (P<0.05), while significantly increasing intestinal ghrelin (ghrelin) and cerebral growth hormone secretagogue receptor (ghsr1a) mRNA expression (P<0.05). No significant effects were observed on cholecystokinin (cck) or its receptor (cckar) expression (P>0.05). In conclusion, dietary SB supplementation enhances growth performance, feed intake, hepatic antioxidant capacity, and intestinal immune function in juvenile Sebastes schlegelii. Furthermore, long-term SB feeding promotes appetite by downregulating leptin and its receptor while upregulating ghrelin expression. Therefore, the recommended dosage of SB in the diet of juveniles Sebastes schlegelii is 2~ 4g/kg.