To establish a simple, efficient and good reproducible method of measuring the content of γ-crystal form impurities in ε-hexanitrohexaazaisowurtzitane(ε-CL-20), the characteristic parameters for the quantitative characterization of γ-CL-20/ε-CL-20 mixed samples were determined by Raman spectroscopy, and then, the characteristic peak area ratio A₂₃₂/A₅₂₈ of two crystal forms was plotted against γ-CL-20 content. The standard curves in the two sets of concentration ranges of 2%-9% and 10%-90% were obtained respectively and compared with the quantitative results obtained by the peak area method. Results show that when the content of γ-CL-20 is 2%-9%, the relative error of A₂₃₂/A₅₂₈ values for three sets of parallel experiments is not more than 2.2%, and the fitting equation is y=0.0062e^0.2512x with a correlation coefficient of 0.9806. When the content of γ-CL-20 is 10%-90%, the relative error of A₂₃₂/A₅₂₈ is not exceed 2.9%, and the fitting equation is y=0.0822e^0.0596x with a correlation coefficient of 0.9816. Data reproducibility and fitting correlation coefficient of A₂₃₂/A₅₂₈ are far better than the peak are method.