The theoretical model of an elastic cantilever with tipmass was established and on this basis, the model of vibroimpact between two cantilevers was obtained. Numerical analysis and experimental validation were taken to investigate the vibroimpact motions of cantilevers excited by harmonic force, and the k=1/1,k=1/2,k=2/2 type of stable periodic motions of the impacted cantilever were presented. At the same time, Poincaré map was established and the Floquet multipliers of the periodic motions were obtained through semianalytical method to determine the stability of the motions at the bifurcation point. These results are helpful to explore the nonlinear phenomena of system with impact such as milling processes.