The oxygen concentration in the glow discharge polymer (GDP) capsule is one of the perturbations that most limit implosion quality. In order to investigate the feasibility of the Rutherford backscattering (RBS) technique for characterizing the oxygen concentration in a GDP capsule, the basic principle of RBS and the experimental conditions are introduced first. Then, the irradiation damage effect of incident ions on the GDP film is simulated numerically. The simulated results demonstrate that the GDP films will be damaged by the incident ions, and the vacancy damage dominates in irradiation modification. Finally, some GDP thin films are measured using RBS, and the oxygen concentration and its depth profile are obtained from the measured RBS spectrum. The simulated and experimental results prove that the oxygen concentration of GDP films can be measured precisely using RBS with an uncertainty of about 3.5%.