The thermostability of La-free and La-modified aluminas derived from different alumina sources including pseudo-boehmite, aluminum sulfate, aluminum nitrate, and aluminum chloride have been studied by characterizations of BET specific surface area (BET) and X-ray powder diffraction (XRD). Further, the activity and thermal durability of monolith-supported Pd catalysts using above different alumina as washcoats for simultaneously catalytic oxidation of C 3 H 8 , C 3 H 6 and CO have been investigated using continuous flowing reaction. The experimental results show that the oxidation activity over the alumina-supported Pd catalysts does not keep in agreement with the surface area of aluminas derived from four aluminum sources. Lanthanum modification improves the activity of all catalysts calcined over 1000 o C for simultaneously catalytic oxidation of C 3 H 8 , C 3 H 6 and CO. Alumina source plays a role on the activity and thermostability of alumina and alumina-supported Pd catalysts. The experimental results show that pseudo boehmite is the best alumina source used for catalytic oxidation at high temperature over 1000 o C.