Abstract: The pyrolysis dechlorination of PVC (polyvinyl chloride) has been carried out by batch operation under atmospheric pressure. The kinetics involved in the PVC thermal decomposition was studied by using thermogravimetric technique. Several tests were carried out at the heating rate of 5-10℃/min, the yields of products and the distribution of chlorine were also studied. The kinetic parameters such as activation energies, reaction orders and preexponential factors under nitrogen atmosphere were calculated by applying Friedmans method. The results showed that the PVC thermal degradation is substantially a two-step process. The first step mainly involves dechlorination of the polymers. HCI is the main volatile product and this reaction can be seen as a first-order reaction. A kinetic model for the thermal dechlorination of PVC has been developed.