Routing of rivers which flow through the important areas is from the important river engineering measures. In this research, flood routing in the Maroon River has been studied bases on hydrometric stations between Behbahan and Chamnezam. Todays, numerical computer methods are developed for the Cent and Nante equations. The HEC-RAS software and Muskingum and Muskingum - corners methods are used for this work. HEC-RAS model with solving of dynamic equations motion simulates unsteady flow in the form of onedimensional flow in open channels. After calibration and testing, the results of these methods were compared.So, the HEC-RAS model results considerably better match with the observational data.