Various thermodynamic databases have been compiled to be mainly applied to the calculation of phase diagrams of alloys, ceramics and so on. The accumulation and assessment of thermodynamic data and phase equilibrium information to establish those databases is sometimes called CALPHAD (Computer Calculation of Phase Diagrams) approach. The CALPHAD has been recognized to be useful in various aspects of materials science and engineering. If the thermodynamic databases could be used to evaluate surface properties of liquid solutions as well as phase equilibria, we would be able to widen not only the applicability of those thermodynamic databases but also the further understanding of the surface properties of liquid alloys and molten ionic mixtures. On the basis of the above concepts, we have applied the thermodynamic databases to the calculation of the surface tension of liquid alloys and molten ionic mixtures. In this paper, we described some of the examples obtained from the above evaluation of the surface properties.