In the present study, combustion mechanisms, activation energy, and exponential constants were investigated for natural pine and acid copper chromate impregnated telephone pole. Oxidative thermodegradation was carried out in air environment at different heating rates by using thermogravimetric analysis. In order to calculate thermal kinetics, the Coats Redfern method was used. There were less flammable products, lower weight losses in the main oxidation region, a decrease in the maximum weight loss temperatures, and more char formation for treated samples as compared to untreated samples. In other words, due to treatment of wood with acid copper chromate, thermal properties of wood changed.