Experiments on separation of the exhaust gas from fusion reactors by using a Continuous Circulation Chromatograph method ( C3 method ) have been performed for use in a fuel cycle of the fusion reactor. In these experiments, a molecular-sieve was selected for the adsorbent material. And, H2/He, D2/He mixed gases and Ar were used as the sample gases and the carrier gas, respectively. It was confirmed that the mixed gases with various composition ratios were continuously separated to each gas composition at a room temperature and below an atmospheric pressure, within a detectable limit of the quadrupole mass spectrometer we used. This separation method can be applied to the D2-T2/He mixed gas and simplify the fusion fuel cycle, where the He and other impurities are directly removed from the plasma exhaust gas within a vacuum pumping system.