Abstract : Lightning is a transient large scale electric discharge phenomena in atmosphere. It is composed of plasma. Since the lightning appears in air, its composition will be based on air (N2 78.084 %; O2 20.9476 %; Ar 0.934 %; CO2 0.0314 % in molar percentage) and water (H2O). The plasma can be in various thermodynamic states. As a matter of fact, the electrical discharge is composed of electrical impulse, thus the chemical equilibrium cannot be reached. The electrical field (10 kV/m ≤ ‖ E ‖ ≤≈ 120 kV/m) can produce thermal non-equilibrium inside the plasma. That is to say the electron temperature is higher than the heavy species temperature. Furthermore, the warmer air rises upwards and can bring some dust and modify the chemical composition of the plasma. In this presentation, we will study the thermodynamic state of the plasma and the influence of dust on transport properties.