As basic studies for clarifying tritium migration and inventory in the solid blanket of fusion reactor, following experimental works have been performed: (1)Sorption (adsorption and absorption) of water vapor on/in the particle of Li2O and LiAlO2 was studied by the breakthrough method. Effects of water vapor pressure, temperature, particle size and bulk density were investigated. Dissociative adsorption on the surface of grain was considered to occur. (2)Exchange reaction between sorbed tritiated water on the surface of Li2O and H2 gas was studied. HT was found to be produced by exchange reaction.