Abstract: Desorption p-t curves of uranium deuteride and uranium tritide were investigated at 225-400 ℃ by using the method of the reaction rate analysis in a constant volume system. The desorption rate constants of uranium deuteride and uranium tritide at different temperatures were determined. The rate of desorption is augmentable along with the increase of temperature and the equilibrium pressure of reaction is increased too. The activation energies of desorption for uranium deuteride and uranium tritide are (26.3±0.4) kJ/mol and (27.7±0.6) kJ/mol, respectively. The data of activation energy indicate that there are no remarkable kinetic isotope effects of desorption for uranium deuteride and uranium tritide.