Abstract: Cold stress is one of the main abiotic factors which can affect the yield and quality of sweet sorghum. To better comprehend the resistant mechanism of sweet sorghum in seedling stage induced by cold stress, and screen the best chilling-tolerance varieties of sweet sorghum, six sweet sorghum varieties were used as materials in this study. The physiological indexes were detected in the leaf under cold stress and recovery treatment. And these indexes were used to evaluate the freezing resistance of sweet sorghum. The principal component analysis and cluster analysis were adopted to evaluate the overall chilling- tolerance of sweet sorghum. The results showed that the content of Pro increased in seedling leaves induced by cold stress.However, SOD, POD, CAT activity and the content of soluble sugar demonstrated different change trends in six sweet sorghum varieties, and the downtrend was also found in some varieties. At last, the six sweet sorghum varieties were divided into three groups based on the principal component analysis and cluster analysis, ‘BJ0603’and‘EN-11’were strong cold-resistant,‘EN-12’,‘IMP-2’and‘KFJT-1’were moderate coldresistant, and‘BJ0602’was weak cold-resistant. These results provide a foundation for screening cold tolerant varieties of sweet sorghum.