Abstract: Based on continuum damage mechanics, the deformation and damage process of composite laminates impacted by projectile were studied theoretically. The basic equations for this simulation were then derived. The composites are of anisotropy and nonhomogeneity, the micro-damage induced by impact is anisotropic and results in nonlinearity of materials, and the local large-deformations of target construct geomet rical nonlinearity. The macro-damages which include cracking of matrix, fibers fracture within lamina and inter face debonded as well are treated by the nodal division for finite element analysis. The projectile made of steel is assumed to be linear elastic and its damage in the impact process is not taken into account. The theory used in this paper can simulate the process of damage and deformation of composite laminates impacted by projectile.