Abstract: In order to better understand the risk of dam-break flooding and to reduce the potential of live and property losses,a Godunov-type coupled numerical model based on one dimensional (1-D) and two dimensional (2-D) modules is developed to simulate different dam-break flows.The Harten-Lax-van Leer (HLL) scheme is used in the 1-D module; while,the Roe's method is adopted in the 2-D module for unstructured meshes.The 1-D and 2-D modules are coup led using an overlapping-region method for exchanging the key hydraulic information.The model is tested with two experimental cases of dam-break flow in the curved channel and in the straight channel with sudden enlargement.Results show that the coupled numerical model is able to simulate the dam-break flow of the two cases with good reliability and applicability.The model has the potential for practical applications in simulating large scale dam-break floods.