Different rare earth La precursors were used to modify Pd/γ-Al2O3 catalyst via incipient wetness impregnation method. C3H8 oxidation performance was studied using powder sample evaluation device and the structures of catalysts were characterized through H2-TPR, XRD, XPS, etc. The results showed that addition of lanthanum effectively promotes palladium dispersion, strengthens Pd-support interaction and stabilizes highly-active Pd2+ species, improving the catalytic activity for C3H8 oxidation. Addition of lanthanum nitrate showed the best promoted-effect in palladium dispersion and stabilization of highly-active Pd2+ species. Compared with Pd/Al2O3, La-modified catalysts showed lower Ts, T50 and T50 values for C3H8 and NO conversion. Lanthanum addition induced changes in metal-support interaction and disperse state of active species play a significant role in enhanced activity for C3H8 catalytic oxidation.