Abstract: In the manufacturing process of composite structures for commercial aircraft, peel ply surface treatment for co-bonding and secondary bonding of composites is becoming more common and gradually substitutes the traditional method such as grinding. And it is found that potential matching exists between different peel plies and composite resin systems in practical application. As a result, varied bonding properties were observed on composite surface with different peel plies after treatments. In order to study the effects of peel ply on the bonding performance, T300/Cycom 970 epoxy resin composite laminates were fabricated using the autoclave process. First, four peel plies and an adhesive film for commercial aircraft were chosen for surface treatment and bonding, respectively. Second, the structure properties of T300/Cycom 970 epoxy laminate specimens after bonding were tested by stripping tests and single lap shear tests according to the ASTM standards. Finally, contact angle test, scanning electron microscopy (SEM) and X-Ray Photo Spectroscopy (XPS) were applied to characterize the surface wettability, morphology and element analysis for composite laminates and peel plies. The results show that the bond quality of the T300/Cycom 970 epoxy composite sample which are treated with polyester wet peel ply is the best, and the residual of peel plies fabric and coating has negative effect on the T300/Cycom 970 epoxy composite bonding performance. Although peel ply surface treatment can improve the surface wettability and the surface energy, the improvement of wettability cannot guarantee the bond quality. T300/Cycom 970 epoxy composite surface topography and roughness are affected directly by peel ply weave pattern, which produce an effect on the bond quality of the composites.