A stable and narrow wavelength spacing multiwavelength erbium-doped fiber laser is proposed and demonstrated. The laser can producesimultaneous dual-and triple-wavelength lasing oscillations with a narrow wavelength spacing of less than 0.1nm via using a singlefiber Bragg gratings written in polarization-maintaining (PM) fiber. By adjusting polarization controller, the wavelength spacing of dualwavelengthlasing oscillations can be tuned to as small as 0.032nm. The maximum amplitude variation for every lasing wavelength is lessthan 0.5 dB. The room-temperature operation principle is based on the polarization hole burning and deeply saturated effect in an ordinaryerbium-doped fiber ring laser (EDFRL). The laser has the advantages of simple all-fiber configuration, low cost, high stability andoperating at room temperature