Prototype experiments on levee breach by overflow show significant effect of vegetation on erosion suppress. This is favorite finding for the levee protection. However, the detailed mechanism is not studied yet. The purpose of this study is to find the fundamental characteristics of flow among the vegetation and to make the mathematical model. Hydraulic experiments were conducted for supercritical flow through inflexible vegetation model. The flow field was measured by laser doppler anemometer. K-ϵmodel was developed to reproduce the velocity profile.