Abstract: The preparation process of certified reference material of kepone in methanol was described. The homogeneity and stability analysis of the raw material of kepone was conducted by gas chromatography coupled with mass spectrometry (GC-MS). The uncertainties caused in the whole producing processes of the reference material were analyzed and evaluated, with comparison of measurement quantity with similar reference materials in foreign countries. The results showed that the certified reference materials are of homogeneity compared with foreign ones, stable for 18 months, and can be used in the environmental monitoring.