Abstract: Numerical investigations were conducted by using the explicit dynamic finite element method. In numerical simulations, the honeycomb specimen was divided into nine regions by referring the local deformation modes of a perfect hexagonal honeycomb under different impact velocities. Based on the above treatment, the influences of the defects (cell wall missing) in different regions on the in-plane dynamic properties of honeycombs were discussed. The results show that except for the cell wall missing ratio, the dynamic performance of the honeycomb relies on the defect location. Especially under middle or low impact velocities, it displays higher sensitivity. The plateau stress relates to the cell wall missing ratio and the impact velocity, whose sensitivity is determined by the defect location.