Poly(styrene-butadiene) (PSB) is pyrolyzed under nit inert atmosphere in different temperature ranges by using differential thermal analysis (DTA) and pyrolysis-gas chromatography (Py-GC). Fourier transform infrared spectrometry (FTIR) is used for investigating the pyrolysis residue. The pyrolyzed gaseous products are analyzed by gas chromatography (GC). The main products are styrene, C-2 hydrocarbons, and vinylhydrohexane. The effect of temperature range on the relative yields of the major decomposition products is studied. Based on these data, the thermal degradation mechanism of PSB is also proposed. It is believed that the pyrolysis process and its products cause no environmental impact.