In order to accurately evaluate the difference of nutritional quality of different purple sweet potato, the nutrient index of water, starch, protein, dietary fiber,anthocyanin, total phenol, flavonoids, vitamin C and vitamin B2 of nine varieties of purple sweet potatoes were determined. Principal component analysis and cluster analysis were conducted to determine the differences in nutritional quality among purple cultivars. The top three varieties were Xu Zishu No. 8 >MianZishu 9 >Yu 7. Chuanzishu No.4, Xuzishu No.8, Xiangzishu 174 are t...