Activated carbon was oxidized with HNO3 at 340 K for 3 hours. The samples thus oxidized were then subsequently heat treated(HT) at various maximum temperatures between 400 K and 1273 K for 8 hours under H2 atmosphere in order to prepare H2 -treated samples. This heat treatment simultaneously allowed carbon-oxygen complexes to decompose progressively and hydrogen to be chemisorbed on the oxidized activated carbons. Temperature programmed desorpion(TPD) in a flowing Ar was then performed from 300K to 1273K on the H2-treated samples to estimate the amount of hydrogen chemisorbed on the carbon surfaces. The amount of hydrogen chemisorbed increased with increasing HT temperature up to about 900 K, above which temperature it decreased. This result indicates that hydrogen chemisorption on the carbon surface strongly depends on the HT temperature and the deactivation of sites responsible for hydrogen chemisorption occurs even at the temperature of 900 K.