Two-fluid system of finite depth is considered in this paper. The fluids have different density, and the height. The interface between them is presented as the lower fluid height measured from the bottom. Because of a disturbance, that height changes at any time and position, so that it presents interfacial wave with KdV equation as the model. The wave propagation and deformation are observed for same various values of the physical parameters, such as density and height of the fluids. A finite difference method is shown successfully in performing the wave propagation.

interfacial wave, KdV equation, finite difference method.