A series of growth experiments was conducted to examine the effect of dietary protein on protein systhesees parameters [protein synthesis rate （Ks）, protein degradation rate （Kd） and protein accumulation rate （Kg） and protein deposition efficiency （PDE） ] in muscle and hepatopancras of topmouth culter, Erythroculter ilishaeformis Bleeker juveniles by using brown fishmeal as the protein source in formulated diets. Tested fish with initial weight （ 12.84 ?0.60 g wet weight）were fed 5 isoenergetic（20 MJ?kg^-1 gross energy ） and the same relativity of essential amino acid balance experimental semi-purified diets containing different protein levels （31.04% ,35.51% ,40.89% ,46.62% ,50.33%dry matter ） in 5% increments. And five isonitrigenous （40% protein） and isoenergefic（20 MJ?kg^-1 gross energy） and different relativity of essential amino acid balance experimental semi-purified diets with soybean protein replacing 0%, 13.5% ,27% ,40.5% ,54% of fish meal protein were formulated. After 8-week trial, The results showed that with increasing dietary protein level, specific growth rate was significantly influenced by dietary protein levels （ P 〈 0.05）. Specific growth rate of the fish fed the 40.89% protein diets was significantly higher than that of the fish fed 31.04% and 35.51% protein diets （ P 〈0.05）, but them was no significant difference from that of the fish fed the 46.62% and 50.33% protein diets （ P 〉 0.05）, Effect of dietary protein levels on protein accumulation rate in muscle followed the similar pattem as that of hepatopancras, protein accumulation rate in muscle and hepatopancras in fish fed the 40.89% protein diets were 2.13%?d^-1 respectively. The specific growth rate of the fish fed the 40.89% protein diets was significantly higher than that of the fish fed 31.04% and 35.51% protein diets （ P 〈 0.05）, but them was no significant difference from that of the fish fed the 46.62% ,50.33% protein diets （P〉0.05）. Protein synthesis rate （Ks） and protein degradation rate （Kd） in white muscle increased with the ubcrease of dietary protein level（ P 〈 0.05） ,protein increase in white muscle was much more due to the increase of Ks than Kd, the muscular protein deposition efficiency （ the proportion of growth to synthesis） had a maximal value in optimistic dietary protein level. When the replacement level for fish meal protein with soybean protein was 13.5%, 27%, 40.5%, them were no significant difference in specific growth rate among the diets compared with control group（ P 〉 0.05） ,and were significantly higher than specific growth rate in fish fed with 54% replacement of soybean protein （ P 〈0.05）. Replacement of fish meal by soybeaa cake also affected significantly the protein accumulation rate （Kg） in white muscle（ P 〈 0.05）. When the replacement level for fish meal protein with soybean protein was 40.5%, there was significant decrease of Kg compared with control group（ P 〈0.05）. When the replacement level for fish meal protein with soybean protein was 54.0%, there was significant decrease of Ks compared with control group（ P 〈0.05）. In white muscle, increased replacement level for fish meal protein with soybean protein did not change PDE （ P 〉 0.05 ）. With the increase of replacement level for fish meal protein with soybean protein, worse EAA balance decreased gradually with the growth, but the change of EAA pattern in diets did not affect PDE of white muscle.