Abstract: A feeding trial was conducted to investigate the optimal dietary L-methionine level for the large yellow croaker (Pseudosciaena crocea R.) larvae from 12 to 42 days after hatching (DAH 12-42). We designed six groups of microdiets (MDs), which contains equal amounts of nitrogen (8. 8%) and energy (16.65 KJ/g). All six groups consisted of natural protein sources from white fish meal, squid meal, and krill meal. Each group was supplemented with crystal L-AAs (except for L-methionine) to simulate the natural AA composition in eggs of large yellow croaker. L-methionine was added into each group at the concentrations (% of diet/dietary proteins) 1.19 /2.17, 1.62/2.95, 2.18/3.95, 2.65/4.81, 3.13/5.70 and 3.66/6.65.Live feeds (Artemia nauplii and copepods) were used as a control diet. Experiments of each diet group, including control, were repeated three times using DAH 12 larvae initially weighted (1.930.11) mg. In every experiment 3500 larvae were fed with a certain diet in a 180-L tank for 30 days. The survival rate and specific growth rate (SGR) of the larvae were measured. We observed that both the survival rate and the SGR increased as the L-methionine concentration (% of diet) was raised, and they reached the peak value at the concentration 2.18. However, higher L-methionine concentrations did not cause further increase in the survival rate. On the contrast, the SGR decreased at higher concentrations. The survival rate and SGR of the control group (live feeds) were significantly higher than all six experimental groups (P0.05). We also measured the whole-body lipid and crude protein (CP) levels of the larvae. There was no significant difference in whole-body lipid or ash content between the experimental and the control groups. There was no difference among the six experimental groups either. However, the whole-body CP increased as the L-methionine level was raised and the CP reached the peak value when the concentration of L-methionine was 2.65 (% of diet). A slight decrease in CP was observed at a higher concentration. Larvae fed with live feeds showed significantly higher levels of CP and the essential AAs than all the six experiment groups (P0.05). Using the second-order polynomial model, we estimated that the optimal dietary L-methionine concentration for large yellow croaker larvae is 2.58% of diet or 4.69% of dietary proteins.