Since the emergence of fiber lasers, the output power of fiber laser has been increased from milliwatt level to myriawatt level along with the rapid development of semiconductor material and fiber fabrication technology. However, with the increasing of output power of fiber laser, many phenomenons which are not shown at a low output power have appeared gradually, such as fiber thermal damage, nonlinearity effect and mode instability, which limit the application of fiber laser. Therefore, the demand for the quality of Yb-doped fiber is higher and higher. The fabrication technologies, doping components and structural design of high power Yb-doped fibers are discussed. The status and development tendency of thermal stability, power stability and mode stability of high power Yb-doped fiber are analyzed.