Aiming at the effect of protease I,protease Ⅱ and lipase in water,the effects of dosages of two kinds protease and lipase, pH value and other factors on soaking were discussed. The soaking effects of different enzymes were compared and the best raw materials and proportions were selected by taking water absorption of leather, the protein content in waste liquid, hydroxy proline content, softness of the soaked skin and yellow heart degree as indexes. The results show that the enzyme can significantly shorten soaking time. When pH= 10, the amount of protease I accounts for 0. 4% of the skin mass, and the amount of lipase accounts for 0. 1% of the skin mass ( the ratio of protease I to lipase is 4 : 1), the best soaking effect can be obtained.