In this study a gas mixtures [CO+N2] are mixed with a specified ratio of 9:1 (N2:CO).The reason for this mixing is that the molecular weight are very close to each other.The main parameters in question to be studied are the diffusion coefficient of the discharge and the related constants to it. The main calculations held that were concerned the plasma discharge operation of optimum thermodynamic constants [Total pressure of 3mb and the discharge temperature of 450Ko]. The results were consistent and very optimum compared with their experimental values, and the optimum circumstance was prepared to use them as an active mediumfor a high power molecular gas laser.