The Raman gain coefficients in polarization maintaining photonic crystal fibers (PM-PCFs) are analyzed in order to design fibers for linearly polarized Raman fiber laser with enhanced performances. The results show that a well designed germanium-doped PM-PCF can attain the value of Raman gain coefficient over 50 /(W.km), going with very high birefringence and single mode operation at 1.55-micron signal wavelength and 1.45-micron pump wavelength.