In this paper

several present microcosmic models of plasma. Potapov’s model

Eindhoren model

the model based on dynamics

and the model based on minimum Gibbs free-enthalpy

are summarized and compared. The fundamentals of the first two models are Dalton’s law

mass action law

charge neutral law and stoichiometric equilibrium condition. But they are different at the formula of mass action law and the partition equation. The last two models describe the microcosmic process of the plasma

based on the chemical reaction

and the basic definitions of thermodynamics and statistical physics

respectively. The variation of the models in the case of equilibrium and non-equilibrium condition is explained. And the Eindhoven’s model is recommended to be adopted in engineering application.