Defects are inevitable in the manufacture and service of composite laminates and their influence on the mechanical performance of composite laminates can be substantial. Ply waviness and delamination are two major types of defects. Compared to the tensile response, ply waviness has more significant influence on the compressive strength of composite structures. To evaluate the effects of ply waviness, experimental and numerical studies are performed. Ply waviness is generated by embedding composite strips in the fabrication of composite laminates. Photomicrographs are adopted to measure the ply waviness. Ply waviness is incorporated into the numerical model using the defects characterization and damage mapping method in our Composite Bolted and Bonded Analysis Toolkit for Abaqus (CB2ATA). A continuum damage mechanics (CDM) approach based on LaRC05 was developed and it is implemented in Abaqus with an implicit scheme. The CDM approach is then adopted in the numerical simulation of composite laminates under compression and the predicted compressive responses are compared with the experimental measurements.