Insulating polyphenylquinoxaline (PPQ) was converted into an electrical conductor by pyrolysis at high temperature in nitrogen. Room temperature conductivity was measured as a function of pyrolytic conditions, and it was found that it strongly depends on the pyrolytic temperature and time. A maximum of room temperature conductivity about 177 S cm 01 for PPQ film pyrolyzed at 1200ЊC for 1 h was obtained, which is 18 orders of magnitude greater than that of the original PPQ film. The current voltage (I-V) curve of pyrolyzed PPQ films follows Ohm's law characteristics of metals. Anisotropy in conductivity along and perpendicular to the surface of the film indicates the formation of a graphite-like structure in pyrolyzed PPQ films. The structure of the pyrolyzed PPQ films was investigated by elemental analysis, X-ray photoelectron spectroscopy spectra, X-ray diffraction, and scanning electron microscopic image. The electrical property and the structural characterizations suggest that the pyrolysis of PPQ films consists of two processes (i.e., carbonization and graphitization), and the critical temperature is at about 800ЊC. During carbonization ( T p õ 800ЊC), some H, N, and O atoms are removed and the temperature dependence of conductivity of pyrolyzed PPQ film can be expressed by the three-dimensional Variable-Range Hopping (3-D VRH) model. During graphitization (T p ú 800ЊC), most H, N, and O atoms are removed from the residue, and a polyconjugated structure forms in it. The temperature dependence of conductivity deviates somewhat from the 3-D VRH model and can be fitted with a modified 3-D VRH model.