A new semi-empirical formula of predicting the self-diffusion coefficient of Lennard Jones chain(LJC)fluid was proposed on the bases of the Chapman-Enskog theory of diffusion and a set of molecular dynamic simulation data for LJC fluid. The new formula adopts two correction functions with six fitted parameters to correct the effect of intermolecular repulsive potential energy and attractive potential energy on the friction coefficient so that it can describe the molecular interactions of real fluid more objectively. The present formula was applied to predict the self-diffusion coefficients of 22 polyatomic compounds over a wide range of temperature and pressure

and the results show that the average absolute deviation of the predictions from the 1 081 experimental data was 3.41%.