Abstract:The fish oil was extracted from the viscera of large yellow croaker by alkaline protease enzymatic hy－ drolysis method.As the extraction rate of fish oil as the experimental index to analyzed the effects of materials/ water ratio， amounts of enzyme，pH value， enzymolysis temperature and enzymolysis time. The enzymatic ex－ traction of fish oil was optimized by orthogonal experiments. The results showed that the optimal extraction con－ditions were as follows： amount of enzyme was 1 250 U/g at pH 8.5， the materials/water ratio was 1 ∶ 8（g/mL） and lasted for 2 hours at 50 ℃. Under these conditions， the extraction rate of fish oil could reach up to 72.45 %， which can be accordance with the national standard of secondary refined fish oil.