Cu-MeO/Ti-SBA-15 catalysts (Me=Mg, Ca, Sr, and Ba) were used for isobutyraldehyde (IBA) synthesis from methanol and ethanol and characterized by various techniques including XRD, N-2 sorption, CO2-TPD, XPS, etc. Doping different alkaline-earth meals (Me=Mg, Ca, Sr, and Ba) to Cu/Ti-SBA-15 can significantly affect catalytic performance in IBA synthesis. Based on characterizations, different alkaline-earth metal doping significantly affects the amount of basic sites and the basic strength of the catalyst surface and their interaction with active Cu and other components. Therefore, the higher activity of the catalyst is closely related to larger amounts of basic sites, stronger basicity, and stronger interaction between Cu and MeO.