We have proposed an approach to achieve nanofibers or composite nanofibers with functional nanoparticles via the protrusion of the budding interfacial membrane in an oil-water emulsion droplet stabilized with copolymers. The nanofibers were formed by the wrapping of the monolayer of the copolymers. The length is tunable with the copolymer concentration and water/oil ratio of the emulsion.