Updated project metadata. In insects, male accessory gland proteins (ACPs) are important reproductive proteins secreted by male accessory glands (MAGs) of the internal male reproductive system. During mating, ACPs were transferred along with sperms inside female bodies and have a significant impact on the physiology of female reproduction. Under sexual selection pressures, the ACPs exhibit remarkably rapid and divergent evolution and varies from species to species. The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a major insect pest of cruciferous vegetables worldwide. The reproductive physiology on post-mating state of this species is still largely unknown, which is important for management of this pest. In this study, the ACPs transferred into females during mating were identified by using a tandem mass tags quantitative proteomic analysis. The MAGs were compared before and after mating immediately. In total, we identified 123 putative secreted ACPs, including most important physiological: regulators of proteolysis, transporters and protein export machinery, signal transduction and immunity. Comparing P. xylostella with other four insect ACPs, trypsins were the only ACPs detected in all insect species. This was the first time to identify and analyze ACPs in P. xylostella. Our results have provided an important list of putative secreted ACPs, and have set the stage for further explore functions of these putative proteins in P. xylostella reproduction.