Studies of the chemical preparation, surface area, pore distribution, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectra (XPS) and acid-base properties of magnesia-alumina composite oxides were carried out. The preparation method led to supports with high surface areas where Mg was homogeneously distributed upon the surface. The base properties of the composite oxides can be controlled by the Mg loading for an optimum catalyst performance.