Plasma is the physical system in which charged particles interact with each other through electromagnetic fields determined by the Maxwell equations. The current density and the charge density included in the Maxwell equations are determined by the motions of the charged particles. The self-consistent coupling between the electromagnetic field and the charged particle motion is schematically shown in Fig. 9.1. The kinetic theory treating plasma as the many body charged particle system is described in this chapter. Since laser plasmas are in high density states where the collisional effects are not negligible in some cases, we derive the kinetic equation including the collisional effects from the Liouville equation.