Abstract: The impact procedure between a rigid body and an elasto-plastic bar with one end fixed is simulated using numerical method. The elastic and elasto-plastic impact loads with different mass ratios and velocities are obtained. The elastic and elasto-plastic numerical solutions of impact load are compared with those of elastic analytical solutions. The calculation results show that: for the elastic impact load, the numerical results are very close to that of analytical ones and there is reasonable ascending part in the numerical results. When mass ratio is constant, the speed of rigid body is proportional to the peak value of elastic impact load but has no effect on the contact time. The mass ratio has an effect on the peak value of impact load and its distributions. The smaller the mass ratio, the larger the peak value of impact load and the longer the contact time. For elasto-plastic impact loads, the plasticity in the bar can cause the reduction of peak value of impact load and change the distribution of load curve. The plasticity can prolong the contact time; the prolonged contact time is the expanding time of plasticity in the bar. The higher the rigid body speed and the smaller the mass ratio, the longer the expanding time of plasticity in the bar and the larger the difference between the elastic and elasto-plastic peak value of impact load and the distribution forms of impact load.