Abstract: Deuterium absorption kinetics of the alloys TiMox（x=0.03, 0.13, 0.25, 0.50, 1.00, Mo/Ti atomic ratio） were studied at the temperature range of 250-650 ℃ by using the constant volume method. The activation energy of deuterium absorption decreases when the content of Mo rises from 0 to 0.25, and increases when the content rises over 0.25, at the temperature range of 450-650 ℃. The activation energy shows negative, when the temperature range is 250-450 ℃. Compared with protium absorption results investigated at previous period, the protium content in alloys is higher than the deuterium content at the temperature range of 250-650 ℃, showing negative thermodynamic isotope effect. At 450-650 ℃, it is harder for the alloys to absorb deuterium, while in lower temperature range, 250-450 ℃, the alloys show more active to absorb deuterium.