A growth trial was conducted to investigate the effects of dietary methionine level on the growth performance and the postprandial accumulated ammonia excretion of juvenile silver perch. Four semipurified (fishmeal-gelatin-soy protein isolated-zein based) diets were formulated to contain 40% crude protein, 10% lipid and methionine levels ranging from 0.50% to 1.40%. All the crystalline amino acids of experimental diets were pre-coated with CMC, Carrageenan and zein to increase the stability. Each diet was fed to triplicate groups of 10 fish (initial average weight of 4.0 g) over 6 weeks. At the end of the trial, percent weight gain was significantly (p<0.05) higher in those of fish fed diets with 1.10 and 1.40% methionine. A similar trend was observed in the feed efficiency. The result indicated that dietary methionine requirement of juvenile silver perch for maximal growth was between 1.10 and 1.40%. The determination of accumulated ammonia-N excretion showed that fish fed lower methionine level diets excreted significantly more ammonia-N.