The results of the research on thermal depolymerization of polypropylene (PP) under a normal pressure are presented. The basic parameter of the process was the applied temperature. Low molecule liquid products of the degradation of the PP were collected by condensation. The composition of the products was analysed by the fractional distillation. The rate of the depolymerization and the composition of the products depended in fact on the process conditions. The catalysts were not applied.