It is well-known that PVC is a troublesome matter in the processes of incineration and recycling etc. because of Cl component giving serious pollutants such HCl gas, dioxin etc. In pyrolysis process, it also causes the problems of corrosion, emission of HCl/dioxin through flue gas, as well as Cl content in oil products In this study, TG analysis and basic pyrolysis experiments were carried out with pure PVC and PVC-based wastes at various temperatures ranges. The test results were discussed related to pyrolysis processes and the results in a commercial plant were discussed together.