MYB is the most important transcription factor in plant anthocyanin biosynthesis pathway. In this study, the anthocyanin StAN1 gene of purple potato was cloned by homologous cloning technique. The results showed that: （1） the full length of the StAN1 gene was 774 bp, encoded 258 amino acids; Phylogenetic tree analysis showed that StAN1 had the closest relationship with pepper, eggplant and asparagus, and had the furthest relationship with Petunia and apple. （2）Fluorescence quantitative PCR analysis showed that StAN1 gene was expressed in different tissues of potato. (3) The expression vector pJAM1502AN1 was successfully constructed by Agrobacterium (Gv3101) transformation to obtain the root, stem, leaf and vein are purplered transgenic tobacco, the expression vector StAN1 gene was transformed from small to large as the root < leaf < stolon < tuber skin < tuber. （3） Transgenic tobacco with StAN1 gene was constructed successfully through Agrobacterium (Gv3101) transformation. PCR identification showed that the target gene StAN1 had been successfully transferred into tobacco. （4） The anthocyanin content of wild type tobacco leaves was 2 mg/g, and the color of leaves was green. However, the anthocyanin content of the transgenic tobacco leaves reached 20 mg/g, and the color of the leaves changed to purplish red.