In the paper, the influence of vibrational and chemical kinetics on heat transfer and diffusion in hypersonic flows of N2/N mixture in the relaxation zone behind shock waves is studied on the basis of the state-to-state kinetic theory approach. The results of calculations of vibrational level populations ni, gas temperature T, total energy flux q, diffusion velocities of molecules at different vibrational states Vi and atoms Va in the relaxation zone behind a shock front are presented for the free stream Mach number M = 10; 15. The contribution of different dissipative processes to the total energy flux is estimated for various flow conditions. The impact of non-equilibrium vibrational distributions in the free stream on molecular level populations and transport properties in the relaxation zone is shown.