Abstract: An analytical model was presented herein for the perforation of ceramic/metal composite armors struck by flat-nosed projectiles using energy balance method. It was assumed that the kinetic energy of a projectile was absorbed by projectile, ceramic tile and backup metal plate during the perforation process. Erosion and deformation (mushrooming) of projectiles, compression/fragmentation and shear failure of ceramic tiles as well as failure modes of backup metal plates with different thicknesses were considered in the present model. For a given projectile and ceramic/metal composite armour, the model can be used to predict the ballistic limit or the residual velocity. The present model predictions are in agreement with now available test data.