Abstract: In this study,10 typical yam cultivars from Shandong,Henan,Hubei Province were selected to investigate the main nutrients that influence cultivars selection of yam using principal component analysis(PCA). The main components were analyzed through principal component analysis,screening a suitable yam cultivars for diabetics.The PCA results showed that 5 principal components could reflect most details on yam with acumulative contribution rate of 93.68%.Ready digestible starch,yam polysaccharide,amylose were the main factors affecting the quality of yam. These 5 principal components rather than the original 12 quality factors were used in comprehensive evaluation of yam.On the basis of the analysis,the principal component comprehensive score model was established,and the highest score of the principal component was Changshan yam,with a score of the 1.175.Changshan yam were selected as the appropriate cultivars for diabetic patients.