Pd-composite membrane for selective permeation of hydrogen was prepared by the deposition of palladium on the asymmetric γ-Al₂O₃ tube purchased from US Filter corporation using the electroless plating method. The thickness of Pd layer was controlled to be less than 5 ㎛. The membrane exhibited high hydrogen permeabilities as temperature increased, and hydrogen selectivities over nitrogen at 400℃ were in the range of 12∼50 depending on pressure differences. When propane dehydrogenation reaction was carried out over the prepared Pd-composite membrane, propane conversion was 2 times higher than the equilibrium conversion by the alleviation of themodynamic equilibrium and the reaction temperature of 80℃ as well.