Chicken feather keratin (CK), a biomaterial that contains a large amount of nitrogen is extracted from chicken feathers and has significant potential for use as a flame retardant. In this study, CK and 9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide (DOPO) were added in different amounts to an epoxy resin (EP), and their flame retardancy and smoke suppression effects were studied. The results showed that CK