The wetting process of a liquid aluminium drop on a solid Al2O3 surface has been investigated. Two different models have been proposed : a hydrodynamic model based on the effect of viscosity as well as a diffusion model which considers diffusional effects. The prediction from the models was compared with experiments. It was found that the wetting process of a liquid aluminium drop on an Al2O3 surface can be represented by the diffusion model rather than by the hydrodynamic model. In contrast, the hydrodynamic model could be employed to describe the wetting process of a liquid polymer drop on a solid.