Olive flounder (Paralichthys olivaceus) is a most important aquaculture species in Korea. Like most marine fishes, olive flounders are stomachless at first feeding and aquired gastric function during the metamorphosis, so food was mainly digested by pancreatic enzyme from first feeding to premetamorphosis. However, comprehensive analysis of pancreatic and gastric digestive enzyme of olive flounder at early developmental period is still unclear. In the expression study of pancreatic and gastric digestive enzyme by real-time PCR at early developmental stage, pancreatic enzyme such as chymotrypsinogen 2, preproelastase 2 and 4, pancreatic protein somatomedin-B domain (PPSB) mRNA expression were initiated at first feeding and strongly expressed in the pancreas developmental stage, while gastric digestive enzyme signal was not at all detected during same period. Although, trypsinogens were secreted from pancreas and have similar amino acid sequence, trypsinogen 3 expression induction was detected both pancreas and stomach developmental stage, while trypsinogen 2 expression was significantly increased only post-metamorphosis period. Pepsinogen mRNA expression was only detected at metamorphosis according to stomach differentiation. Lipid digestive enzyme, lipase and intestine fatty acid binding protein 1 (I-FABP 1), were already reached a certain level at beginning of hatching and more increased during early developmental stage and then gradually decreased before metamorphosis. These results suggested that feed ingestion of olive flounder was exclusive charged by pancreatic digestive enyme, lipid digestive enzyme and trypsinogen 3 from first feeding and then fully swiched by gastric digestive enzyme and trypsinogen 2 from metamorphosis period.