Abstract: The visceral crude lipase was extracted in phosphate buffer saline and partially purified by ammonium sulfate fractionation.The effects of different reaction temperature and p H on crude enzyme activity and stability were studied. In the application of tilapia skin degreasing, the single factor test and response surface test were used to optimize the fish skin enzymatic degreasing process. Experimental results showed that the specific activity, purification factor and purity after ( NH4) 2SO4precipitation reached 12.60 U/mg, 6.06 and 81.65%, respectively. The optimum temperature and p H was 45 ℃and 8.0, respectively.The crude lipase was relatively stable between 0⁵0 ℃ and in the p H range of 6.0¹1.0.Additionally, the crude lipase was found to be effective in degreasing of tilapia skin. The results showed that the degreasing rate of tilapia skin reached 67.02% ± 1.61% under the conditions of enzyme addition of 90 U/g, p H value of 7.5, temperature of 37 ℃ for60 min, indicating that the crude lipase could be effective in the removal of fish skin fat in mild conditions. The results offer experimental basis and theoretical reference and practical foundation for further study of the high value utilization of golden pompano processed waste.