Cod oil was extracted by papain hydrolysis. The technology was optimized by single factors and response surface tests according to the extraction rate. The technology was compared with traditional dilute alkaline hydrolysis in the aspects of cod oil extraction rate and quality. The result showed that the optimum condition of enzymatic technology was as follows: ratio of solid to liquid 1∶1.5, pH 6.5, the quantity of enzyme 3 270 U/g, temperature 50 ℃and enzymolysis time 2 h. The extraction rate of the optimal technology could reach 93.44% and the obtained fish oil had good quality with acid value 5.49 mg/g, iodine value 148.31 g/100 g and peroxide value 7.49 meq/kg. The extraction rate and quality of cod oil extracted by the enzymatic hydrolysis was prior to that extracted by the diluted alkaline hydrolysis method.