The Yb 3+ doped double clad silica fibers with rectangular and other novel inner cladding have been made by using modified chemical vapor deposition process, solution doping and optical machining altogether. The operation of these cladding pumped fiber lasers is demonstrated. The maximal laser output of rectangular fiber laser is 84 mW at the wavelength 1075.6 nm, and a slope efficiency of 77% has been achieved.