Abstract: A series of supported perovskites La_0.8Sr_0.2MnO₃/SBA-15 catalysts were prepared by step coating NH₃/water vapor-induced internal hydrolysis method, and characterized by XRD, BET, TG-DTG, XPS and H₂-TPR. Their catalytic performances for toluene combustion were evaluated on a continuous-flow fixed-bed reactor. The results showed that step coating NH₃/water vapor-induced internal hydrolysis method is favorable for the entrance of La_0.8Sr_0.2MnO₃ into pore structure of SBA-15, and the formation of perovskites phase. The formation of perovskites crystal and lattice oxygen can provide more active sites, promote the catalytic activity of toluene combustion.