Abstract: New correlations based on group-contribution method for estimating critical properties have been proposed with con-tribution values of 67 groups.The new correlations have been examined by extensive comparison of the values calculatedwith the experimental data of 275 substanees.The average percent deviations of estimation of T_c,P_c and V_c are respective-ly 0.76,2.73 and 2.50 which are lower than those estimated by the Lydersen method and the Ambrose method chosenfor eomparision.

摘要： New correlations based on group-contribution method for estimating critical properties have been proposed with con-tribution values of 67 groups.The new correlations have been examined by extensive comparison of the values calculatedwith the experimental data of 275 substanees.The average percent deviations of estimation of T_c,P_c and V_c are respective-ly 0.76,2.73 and 2.50 which are lower than those estimated by the Lydersen method and the Ambrose method chosenfor eomparision.