Abstract: A numeral model of erosion for carbon-based materials impacted by hypervelocity particles was established based on dynamics. The parameters characterizing the capability of materials resistance to erosion , impactdamage erosion energy and shear damage erosion energy were int roduced in this model. The theoretical formulas ofthe volume loss caused by particles impacting were obtained by defining a multiple impact s modifying factor β. Theextent of erosion of graphite and C/ C composite was calculated while the impact angle and velocity of Al₂O₃ particlesvaried. The result s indicate that , although both forms of mechanical damage would take place simultaneously , themechanism of carbon-based materials appears to be the impact damage caused by normal force. The calculationresult s achieved by the present method well agree with the experimental data in the related literature.