In the fields of operation and handling of the hydrogen isotope facility, and of management technology for the nuclear fusion source, gas chromatography has been used as one of the practical techniques for the separation and the enrichment of hydrogen isotopic gases including tritium. Chromatographic separation experiments of the hydrogen isotope mixture (hydrogen, deuterium and tritium) were carried out by use of a commercially available gas chromatograph. An aliquot of the gas sample was injected with a specially designed vacuum sampler into the stream of inert carrier gas which goes through the separation column at liquid nitrogen temperature. The complete separation of hydrogen isotopic molecules was observed with an alumina adsorbent partially deactivated by coating with 10% manganese chloride. In addition, fairly good separation conditions without appearance of the nuclear spin isomers in a shorter retention time, which would be useful for the practical applications of the hydrogen isotope separation and enrichment, were obtained.