Pyrolysis gas chromatography (PGC) equipped with carbon diozide Laser pyrolyzer was used for rapid determination of monomer component composition of acrylonitrile-butadiene copolymers. Relative ratio of peak height of the acrylonitrile to butadiene in the pyrograms exists good linear relationship with monomer component composition of the corresponding copolymers. Employing a standard curve, three samples of acrylo-nitrile-butadiene robber with unknown composition were determined conveniently, The results show that the results from laser pyrolyses agreed quite well with those from chemical analyses.