Abstract: Flavonol,as an important type of flavonoids,is an important class of secondary metabolites that widely distribute in plants and is closely related to the nutrient and appearance quality of plants. The expression pattern and the expression level of the key genes of flavonol biosynthesis are important factors that determine the biosyhthetic process and contents of flavonols. Therefore,understanding the research progress on key genes of flavonol biosynthesis is of great significance to the effective regulation of biosynthesis of flavonols in plants. In this paper,the latest research progress on the clone,distribution,characteristics and the responses to the outer environmental conditions of the key genes(PAL,C4H,4CL,CHS,FLS)on flavonol biosynthetic pathways were reviewed,in order to provide reference for future studies on flavonol biosynthesis.