Abstract: Based on the concept of functionally gradient characteristics, a numerical simulation model of honeycombs with graded yield stress is developed. The effects of graded yield stress and impact velocity on the in-plane impact performance are discussed in detail. The research results show that the deformation modes are dependent on the values of graded yield stress. Through proper adjustment of the yield stress gradient, the values of the stress transmitted into the structures can be greatly reduced and the energy absorption can be controlled effectively. These results can provide theoretical guidance for the study and design of yield stress graded honeycombs.