The effect of hydrogenation on the magnetic ordering temperature and magnetostriction of the Tb0.27Dy0.73Fe2 and Tb0.27Dy0.73Co2 compounds with compensated magnetic anisotropy of the rare-earth sublattice was studied. It was established that the incorporation of hydrogen atoms into the crystal lattice of the compounds studied lowers the Curie temperature. It is shown that, in this case (i.e., for structures of the Laves phase type), the decrease in T-C results primarily from the change in the electronic structure of these compounds. An anomaly was found in the temperature dependence of thermal expansion of Tb0.27Dy0.73Co2 and its hydride. It was established that hydrogenation brings about a substantial weakening of magnetostriction, which should be attributed to a change in the local electronic density induced by the incorporation of hydrogen atoms into the crystal lattice. (c) 2005 Pleiades Publishing, Inc.