Abstract:In order to let kenaf cytoplasmic male sterile(CMS)lines and maintainers in southern China live through the winter safely and to realize perennial cultivation,propagation of male sterile lines will be fixed in the lower backcross generation.Kenaf cytoplasmic male sterile(CMS) line P3A and its maintainer P3B were grafted on the kenaf wild species H040,hybrids P3A×H040,and its grafing were used as controls.The results of cluster analysis and membership function showed that cold resistance may be divided into 5 categories,level 1,the most:kenaf wild species H040 and hybrids P3A×H040; level 2,strong:P3A/P3A×H040 and P3A/H040; level 3 medium:P3A CK and P3A/P3B; level 4,Less:P3B/P3A×H040 and P3B/H040; level 5,the weakest:P3B/P3A and P3B CK.Main composition analysis showed that the first principal components were withered degree,soluble sugar content,conductivity,number of leaves; The second principal component was water content of stem.Kenaf scion cold resistance on grafted by strong seedling rootstocks was improved.