Diseases has become a serious problem in aquaculture recently years. The research of non-specific immune factors of the cultured aquatic animal have been taken into account. Lysozyme is one of the important nonspecific immune factors in body. In this article, the biological function, molecular cloning, genetic engineering and expression in body of lysozyme were summarized. At the same time, the applications of lysozyme of aquatic animal in aquaculture disease prevention were discussed.