Abstract: The calculation result of the impact force of the rolling stone obtained by the conventional method is much larger than that under the actual working condition. In order to improve the efficiency of the engineering design, an impact force calculation method is developed by considering the elastoplastic characteristics of the material for two structures, i.e., the cantilever beam and the simply supported beam. Based on the conservation of energy, the energy conversion processes during the impact of the rolling stone and the structure under load are classified into distinct stages. The maximum indentation deformation of the structure after the load was calculated, and the maximum impact force of the rolling stone was determined. Finally, the method developed in this paper was applied to a practical engineering problem, and the results were compared with those obtained by LS-DYNA. It is found that the present method provides better results than those calculated by Hertz elastic contact theory or by the method recommended by the "Code", when comparing calculations with practical measurements.