A series of Cu-Mn-Al catalysts with different Mn content were synthesized by co-precipitation method using Cu(NO3)2, Mn(NO3)2, Al(NO3)3 and Na2CO3 as raw material. The samples were characterized by BET, XRD, SEM, TEM, H2-TPR and NH3-TPD. The catalytic activity was tested by 1-methoxy-2-propanol dehydrogenation to methoxyacetone in a fixed bed reactor. The results showed that Mn content had great effect on the pyhsico-chemical properties of Cu-Mn-Al catalysts. The addition of appropriate Mn promoted the dispersion of Cu, changed the reducibility and reduced surface acidity. When n(Cu):n(Mn):n(Al)=2.0:3.5:1.0, the surface acidity of Cu-Mn-Al catalyst was the lowest and Cu-Mn-Al catalyst had lower reduction temperature. Under the reaction conditions of reaction temperature 260 ℃, reaction pressure 1atm, 1-methoxy-2-propanol feed with 5% mass fractions of water and liquid hourly space velocity 2.5 h-1, the conversion of 1-methoxy-2-propanol was 61.57%, the selectivity of methoxyacetone was 96.83%, and the selectivity of main byproduct acetone was 1.20%.