This article is about flow over rippled bed considering unsteady, incompressible viscous flow with free surface. The method solves the two dimensional Navier-Stokes equations for conservation of momentum, continuity equation, and full nonlinear kinematic free-surface equation for Newtonian fluids, as the governing equations in a vertical plane. A mapping was developed to trace the deformed free surface by transforming the governing equations from the physical domain to a computational domain. Finally, a numerical scheme is developed using finite element modelling technique to predict the flow over ripples with using Arbitrary Lagrangian Eulerian algorithm. The results are compared with other researches and gave good result.