This experiment aimed to investigate the effects of protein and lipid levels on growth and physiological factors of Pelteobagrus fulvidraco larvae in recirculating aquaculture system (RAS). A random 2×2 two-factors animal experiment including two different protein levels (48%, 52%, P48, P52) and two lipid levels(9%, 13%;L9, L13) was used to formulate 4 trial diets. Each treatment had 3 replicates and 3600 individuals per replicate. The trial fish was P. Fulvidraco larvae at 2 day after hatching that was fed Artemia naupliias initial feeding for 1 day, and gradually transformed to trial diets. The conversion period of feed was 2 days. The research was conducted for 21 days. The results showed as follows. ① High protein and lipid level of diets significantly improved the survival rate(SR), weight gain rate (WGR) and feed conversion rate of P. Fulvidraco larvae with the univariate analysis.The double factors analysis indicated that P52L13 diet significantly increased the SR of trial fish compared with P52L9, P48L13 and P48L9 diet, and exceeded by 32.67%, 22.21% and 14.54%, respectively. The WGR of trial fishin P52L13 diet increased by 40.15% and 43.74% compared with P48L13 and P48L9 diet. P48L9 diet improved the SR by 15.83% and 7.21% compared with P52L9 and P48L13 diet, but the WGR was the lowest. ② The physiological factors results showed that the single factor (high protein and lipid level of diets) significantly improved IGF-1 and T3 levels of trial fish, and had a tendency to raise enzyme activity of digestion and absorption. Double factors analysis showed that the enzyme activity of digestion and absorption, IGF-1 and T3 levels of trial fish in P52L13 diet were higher than others. The activity of lipase, amylase and AKP of the trial fish in P48L9diet were higher than P52L9 and P48L13, but the Na⁺-K⁺-ATPase activity, IGF-1, T3 and GH levels were the lowest. ③ The new discovery of this study was that the trial fish with P48L9 diet had higher SR, feed intake, enzyme activity of digestion and absorption than P52L9 and P48L13, but the lowest WGR, growth related hormone level than others. It indicated that the lower protein and lipid level had an negative effect on trial fish growth, but benefited the survival ability when the protein to lipid ratio was appropriate. In conclusion, the change and interaction of dietary main nutrient elements affected growth and physiological factors of P. Fulvidraco larvae. This research shows that the P52L13 diet is the excellent combination giving consideration to SR, growth, digestion and absorption ability, growth related hormone level of P. Fulvidraco larvae in RAS. The P48L9 dietary combination with appropriate protein to lipid ratio can enhance the survival, digestion and absorption ability of P. Fulvidraco larvae. Therefore, the appropriate protein to lipid ratio has important significance for the survival and development of fish in the early stage.