The Landau-type theory of inhomogeneous systems is applied to study the surface melting of aluminum. In order to describe the bulk properties, the potentials obtained ab initio for aluminum by Straub et al. are introduced. Conditions for appearance of surface melting and surface non-melting are formulated. It is found that the calculated surface melting temperature depends on parameters of the theory and is always lower than that obtained experimentally for AI(110) face. The temperature dependence of the quasi-liquid layer thickness exhibits logarithmic behavior in accordance with the experiments. The parameters of the theory can be correlated with experimentally verified quantities.