The Pd/SAPO-5 bifunctional catalysts were prepared by hydrothermal method, with triethylamine as the template, for one-step synthesis of methyl amyl ketone (MAK) from acetone and butyraldehyde. The influences of n(SiO2):n(Al2O3) and reaction temperature were investigated, and the properties of catalysts were characterized by H2-TPR, XRD, SEM, XRF and 29Si MAS NMR. It’s proved that while the doping of Pd didn’t change the molecular sieve crystalline structure of SAPO-5, the alteration of n(SiO2):n(Al2O3) could induce the changes in crystalline structure and morphology of SAPO-5. With the SAPO-5 crystalline structure kept intact, the activity of Pd/SAPO-5 rose with the n(SiO2):n(Al2O3). For the catalyst with the best n(SiO2):n(Al2O3) of 1.5 and operated at the optimized 180 ℃, the yield of MAK can be 58.2%, which is rather stable under 500h time-on-stream test.