With increasing output power of fiber lasers, the fabrication of high power laser fiber requires larger sized core rod and more precise control of the refractive index profile of rare earth doped fiber preforms. However, most of the existing preparation techniques of rare earth doped silica fiber preforms are based on the processes which were used to produce communication fibers and their limitations have gradually emerged. Therefore, it is urgent to develop new techniques to fabricate high power laser fiber performs. In this paper, some newly developed preparation processes of rare earth doped silica fiber preform are elaborated, and then their advantages and shortcomings are discussed in detail.