Abstract: The recombinant vector pBI121-DchCHS1-GUS was transformed into agrobacterium GV3101,and the influence of DchCHS1（KX893854）on the color of D.chinensis was studied by agrobacterium infection method,in order to establish a rapid identification system for gene function of D.chinensis.The results showed that after DchCHS1 overexpression,CHS activity and flavonoid content increased significantly,but the flower color became lighter and some parts faded,and the content of anthocyanin in petals decreased significantly.In conclusion,chalcone synthase（CHS）was a key enzyme in plant flavonoid synthesis and anthocyanin synthesis pathway.Screening and identification of CHSgene was conducive to the study of flower color improvement and metabolic engineering.