Abstract: This work carried on a numerical simulation of evolution laws of the main particles in Ar plasma with time-variation under different initial temperatures. The changes of concentration of various main particles with time-variation were tracked, and the evolution laws of concentration of main charged and neutral particles in discharged Ar plasma were obtained. The results show that the time required for Ar plasma chemical reaction to reach equilibrium is reduced with the increasing of initial temperature. The concentration of active particle Ar⁺ increases with time, the concentration of Ar^*, Ar^** firstly increases and then decreases with time, and finally reaches equilibrium.