To evaluate the chemical properties of the epsilon particle present as a precipitate in the high-level radioactive waste, we performed the experiments for the samples fabricated by CeO2 containing 1, 3, and 5wt%Mo, where CeO2 is used as the simulated high-level radioactive waste to replace the real one, using X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEMEDS). Moreover, to evaluate the chemical behavior of Mo epsilon particle in CeO2 at high temperature, the manufactured CeO2-1wt%Mo, CeO2-3wt%Mo, and CeO2-5wt%Mo samples were heated at 100, 300, 500, 700 and 900ºC for 7 h in a tube furnace under Ar atmosphere. In this study, the results of comprehensive analysis including the crystal structure, chemical state, and elemental distribution will be presented to verify the chemical properties for CeO2 samples containing Mo epsilon particle, depending on the Mo content and heating temperature.