We studied the doping effects of K(alkali metal) and Mn(transition metal) on the catalytic activity of MgO(basic metal oxide). The addition reaction of acetonitrile and methanol was selected as a model reaction. The doping of K and Mn on MgO enhanced the catalytic activity of MgO resulting in the increase of acetonitrile conversion. In case of K-doping on MgO, propionitrile formed by addition reaction of acetonitrile and methanol was the main product. Whereas, in case of Mn-doping on MgO, acrylonitrile formed by dehydrogenation of propionitrile was the main product. Even though K doped on MgO enhanced the addition reaction between acetonitrile and methanol by increasing the basicity of MgO, it could not act as dehydrogenation site. On the other hand, Mn doped on MgO, which existed as a form of MnO, not only enhanced the addition reaction but also acted as dehydrogenation site.