Abstract: In this paper the kinetics of the laser decomposition process of eight kinds of polymers has been studied. In plotting the decomposition speceis concentration vs.time,a series of similiar S-shape curve was obtained,indicating that there is an analogous kinetic beavior for the polymers decomposed by laser. When the middle and the last portion of the S-shape curves was treated as a first-order and zero-order reactions respectively, the correspoding rate constants were obtained. As the authors considered, the initial stage in the course of the laser radiation is an inductive stage of excitation, on which a certain explanation has benn given in the paper. The turning points of the upper portion of the S-shape curves vary with the kinds of polymers studied and could serve as an important parameter,characterizing the structure of the polymers.