Hydrogen absorption-desorption properties of UZr2.3, 6-phase intermetallic compound, were studied at temperatures ranging from room temperature to 973 K at a hydrogen pressure of 10 to 105 Pa. As a result, separation into ZrH2 and UH3 phases occurred on hydrogenation of UZr2.3. However, the decomposition isotherms of these phases were considerably different from those of the respective pure metals, and this result was attributed to the dissolution of one metal element into the hydride phase of the other metal element. Despite the formation of the UH3 phase, powdering of the alloy specimen on its hydrogenation was remarkably reduced, possibly due to zirconium dissolving into it. Hence, the UZr2.3 is evaluated to be a promising storage material for tritium.