The photocatalytic decomposition of water for H2 evolution over 1 wt% Ni/CsLa2Ti2NbO10 was carried out according to the reoxidation time interval. The dependence of photocatalytic activity on the reoxidation time interval was examined by XRD, UV-vis, TEM, TPR and XPS. With the increase in the reoxidation time interval, the H2 evolution increased gradually and the maximum H2 evolution (212 μmol/h.g-cat) was observed when reoxidized for 2 hrs. This is because of the small particle size of 10 nm and homogenous Ni/NiO distribution. The drastic decrease of photocatalytic activity for samples reoxidized for 4 hrs was due to the partial formation of NiO bulk phase and the growth of nickel particles.