A new derivation of transport properties in a two-temperature plasma has been performed. The electron kinetic temperature Te is supposed to be different from that of heavy species Th. The resolution of the Boltzmann's equation, thanks to the Chapman-Enskog method, is used to calculate transport coefficients and it allows to the generalisation ofbracket integrals out of thermal equilibrium. Two-temperature diffusion coefficients are defined and the obtained results are presented for an atmospheric two-temperature argon plasma
