Kinetic tests on pyrolysis of polypropylene were carried out by thermo gravimetric technique heating the sample at the rates of 0.5, 1.0, 2.0 ℃/min in a stirred batch reactor. The activation energy and the reaction order were determined at conversions from 1 to 100%. The activation energies increased slowly from 208 kJ/mol to 288 kJ/mol and the reaction order was 0.01. Polypropylene was thermally cracked in a semi-batch reactor at 410-430 ℃ for 60 minutes. As the reaction temperature increased, the yields of product oil increased. However, the selectivity of specific hydrocarbons was not observed.