Abstract: The factor analysis of 16 physical property indexes such as breaking strength,breaking toughness of sewing threads was undertaken using the statistical products and service solutions(SPSS software).Three factors were chosen according to the criteria of eigenvalues> 1 and factors cumulative contribution root> 80% ~ 85%.Then four clusters were obtained by cluster analyzing of the three factors.The comprehensive physical properties of clusterⅠandⅡare fairly good,clusterⅢis moderate,and clusterⅣis relatively poor.At the same time,by means of regression analysis on factors,regression models of the relationship between evaluation indexes of seam quality which includes seam cockling,seam breaking strength,seam breaking elongation and the three factors were established,which could be used for estimating the seam quality of sewing threads.