This study investigated the tensile damage progress in stitched laminates experimentally and numerically. Particularly, the effects of stitching on the damage progress was focused. First, it was experimentally confirmed that ply cracks and delamination appeared under loading regardless of the stitching. We then performed damage extension simulation for stitched laminate using a layer. wise finite element model with beam elements as stitch threads, in which the damage (ply cracks and delamination) was represented by cohesive elements. The detailed comparison between the observa-tion and the simulated results confirmed that stitching has few effects on the onset and the accumula-tion of the ply cracks. Furthermore, we demonstrated that the stitch threads significantly suppresses the extension of the delamination.