Abstract: The equilibrium desorption isotherms curves(PCT curves), the characteristics of tritium heels of tritium reacting with LaNiAl alloys which aged for 300, 1 000, and 1 200 days were investigated at constant temperature and volume in our metal hydride research system, and the process of protium exchange tritium heels was also studied. The results show that LaNiAl alloys have significant tritium aging effects with an increase in the aging time, which include the isotherms change, decreasing the desorption pressures, increasing the isotherm plateau slopes, decreasing the total storage capacity, and increasing the tritium heels. The model of tritium heels vs aging time was established and compared with the results of American tritium aging experiments. Exchange of the tritium with the lighter isotopes protium is an effective method for remove of residual tritium from aged LaNiAl alloys. In the study, 10 exchange cycles are effective in reducing the tritium inventory from T/M=0.128 27 to 0.000 02, and the tritium heels are almost recovered.