Abstract: Starting from the indentation damage mechanics, a numerical model of laminated composites subjected to quasi-static indentation was established on the basis of progressive damage mechanics. The different kinds of composite damages and their progressive processes were quantitatively analyzed. Furthermore, under the condition of same laminates thickness, the effect of single ply thickness on the indentation damage was discussed. The results show that the increase of single ply thickness can enlarge the matrix damage and the delamination degree, whereas it can restrain the development of fiber fracture.