Surface field electron emitters using a carbon nanotube yarn and a method of fabricating the same are disclosed. To fabricate the carbon nanotube yarn for use in fabrication of simple and efficient carbon nanotube field electron emitters, the method performs densification of the carbon nanotube yarn during rotation of a plying unit and heat treatment of the carbon nanotube yarn that has passed through the plying unit without using organic or inorganic binders or polymer pastes. The method fabricates the carbon nanotube yarn with excellent homogeneity and reproducibility through a simple process. The carbon nanotube yarn-based surface field electron emitters can be applied to various light emitting devices.