Abstract: Group modify index was adopted to describe the molecular structure of polychlorinated dibenzofurans （PCDFs），and a quantitative relationship model between the RI，RRT value and the molecular structure index of PCDFs was established by linear regression. Eight models，each of which was constructed by using all sample sets，with high correlation coefficient r>0.97，were developed for three columns（DB-5，SE-54 and OV-101），with mean relative deviation of 1.09% to RI.The RI and RRT of other PCDFs molecules were predicted by the regression equation，and error analysis was discussed. The results showed that the model developed could achieve better agreement between predicted and observed mean values of the same atomic values of chlorinated dibenzofurans than those predicted in literature.