In this study, the copyrolysis of waste wood chip (WC) and block polypropylene (PP) was studied to investigate how the characteristics of bio-oils are affected by copyrolysis. The thermogravimetric analysis performed with a temperature rise of 20 ℃/min, from room temperature to 600 ℃, showed that the decomposition temperature of PP was a little higher via copyrolysis than the single-component pyrolysis. This result suggests that the characteristics of the pyrolysis of PP were affected by the pyrolysis products of WC. The Py-GC/MS analysis of the copyrolysis products detected some new compounds that had not been detected in the single-component pyrolysis products, indicating interactions between the products of WC and PP pyrolyses. The results of the experiments using a fixed bed reactor showed improved properties of the bio-oil obtained from the copyrolysis compared to those of the bio-oil obtained from the single-component pyrolysis: increased carbon and hydrogen contents, decreased water content and a significantly increased heating value.