Random distributed feedback fiber laser (RDFFL) has been developed as a new type of fiber laser in recent years. RDFFL belongs to random lasers since the feedback of laser light depends on the random distributed fiber Rayleigh scattering, rather than reflection mirrors. It achieving gain through distributed fiber Raman scattering, is regarded as a new light source with stable, incoherent continuous-wave (CW) output, with potential applications in nonlinear optics, optical communications and sensing areas. The working principle, research progress and applications of RDFFL are introduced.