The objective of this report is the investigation of transport and thermodynamic properties in nonequilibrium polyatomic gas with rotational and vibrational degrees of freedom. In Part I the modelling of transport processes in diatomic gas is presented, in Part II the three-atomic gas CO₂ is considered. The method is based on kinetic equations for distribution functions. The theoretical formulas for pressure tensor and heat flux in nonequilibrium conditions are given. The practical algorithm of calculation of shear and bulk viscosity, heat conductivity and diffusion coefficients is developed. The results of the calculation of nonequilibrium specific heats and dissipative coefficients in N₂ and CO₂ are given in curves and tables for the temperature interval 300-10000K in N₂, and 300-5000K in CO₂. A comparison of the results of this study with the ones obtained on the basis of other models and in experiments is presented. The effect of rotational and vibrational excitation on transport properties is shown; and interpolating polynomials for the transport coefficients given in the tables are provided.