Abstract: The plant secondary metabolites has many important physiological functions and its microbial transformation has become a hot research topic in this field in recent years. In this paper, several species and function of plant secondary metabolite had been summarized. Meanwhile, various types and characteristics of microbial transformation of plant secondary metabolite had been introduced. Moreover, it was predicted that microbial transformation would have wide application prospect in production of bioactive substances and development of pharmaceuticals and health foods.