Abstarct: Stepped spillway is considered as a important structure in energy dissipating along chute dam engineers. In order to investigate energy lose, a stepped spillway was modeled in two situations non-edged step and edged step with 1.5 cm thickness and 1، 3, 5 cm height. It was simulated by two dimensional fluent software. Simulation of the two-phase flow carried out by pattern of open channel fluid volume and flow was simulated by k-ε turbulence RNG model. Results of numerical model showed good agreement with experiment results. Results showed that in two situations, non- edged step and edged step as increasing of discharge، relative energy lose decreased. Also energy lose was more in the case of edged steps then non-edged steps. In the case of installation edged at first end at mid of the step separately on edged with 1cm height was considered as the proper one. Energy dissipation for 1 cm height edge at the mid of the step was about 94.16% which compere to 1cm height edge at the end of the step showed 1.86% increase relate to non-edged step. When the edges at the same time installed at the first and at the middle of edge with 5cm showed the best results. In situation which edged simultaneously installed at the first and mid of the step the best model was, edge with 3ch height at the end and 5cm height the mid end compere to other models energy lose was about 94.04% which lnoreesed energy dissipation 1.73% related to non-edged model. In the case that the first edge was constant and the middle edge was changeable as increasing of edge height at the middle of the edge, energy lose was increased.