We fabricated reduced graphene oxide fiber through wet spinning and chemicallyreduction method. We observed the reduction of graphene oxide by using Ramanspectroscopy and X-ray photoelectron spectroscopy. The mechanical and electrical propertiesof reduced graphene oxide fiber were also measured and both properties wereimproved by reduction of graphene oxide fiber. We applied the reduced graphene oxidefiber to electrode for the electron emission. The emission current was 1.0 mA and the fieldenhancement was 4.97×103. It shows that the reduced graphene oxide fiber would beapplicable as a material for electron emission.