The extraction conditions of the collagen in the skin of Monopterus albus are studied in this paper. The extraction conditions are optimized by experiment to five factors of extraction time of supersonic,the addition of trypsin, temperature, pH and the decomposition time of enzyme. The result shows that the optimum conditions are supersonic extraction time 3min, the amount of 150U/g ftrypsin, pH7.2, temperature of 35℃, the decomposition time of enzyme 7 hours ,and the extraction rate of collagen is 92.4%. Collagen are analyzed by UV and IR. The result shows that the λmax of product is 226 nm and the functional groups of collagen have peptide bond, carbonyl, carboxyl etc.