Effect of 4-nonylphenol (4-NP), endocrine disrupting compounds (EDCs), on glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) were investigated in the plasma of juvenile rockfish, Sebastes schlegeli. Fish were injected with 4­NP (10, 50, 100 and 200 mg/kg body weight) in $70\%$ ethanol twice at 3-day intervals and plasma sampling were extracted at 7 days after the last injection. Controls received solvent only. 4-NP significant increased GOT in a dose-dependent manner. GPT was markedly elevated to $61\%$ (P<0.05) and $82\%$ (P<0.01) than that of the control at the 4-NP doses of 100 and 200mg, respectively. These results suggest that the estrogenic activity of 4-NP increase plasma GOT and GPT by toxic effect on hepatocyte.