Abstract: A 3D mathematical modeling considering bank erosion is developed by using both a cohesive bank erosion model and a 3D flow-sediment transport model.The locally-adaptive grid system based on the non-orthogonal grid is proposed to simulate the lateral migration in the channel due to the bank erosion.The governing equations for flow-sediment transport are solved with the finite volume method and the SIMPLEC algorithm with the momentum interpolation.The computed case of the self-forming meander evolution demonstrates that this model is able to predict the complex fluvial processes in alluvial rivers with bank erosion.