Abstract: A series of experimental tests on roughening method with grass cushions were conducted in this study. The ranges of roughness induced by different grass cushions were determined and a relationship of roughness versus Froude number obtained. We also analyze the influence of these cushions on the bottom flow and suggest the minimum flow depths suitable for application of the roughening method. The method was applied in hydraulic model tests on integrated schemes of regulating the Qian’an reach of the Luan River. The experimental results illustrate that the enhanced roughness by grass cushions satisfies the requirements of hydraulic modeling, and improves the modeling results of the characteristics of river channels.