Simultaneous continuous-wave multiwavelength operation of a Raman fiber laser is demonstrated with sampled Bragg grating (SBG) at room temperature. The characteristics of multiwavelength fiber ring laser can be easily controlled by adjusting the parameters of the SBG, including the sampling period and the sampling length. In the proposed fiber laser, stable four oscillating wavelengths with 100- and 50-GHz spacing has been achieved, respectively, as well as five oscillating ones with a wavelength spacing of only 25 GHz by varying the sampling period of the SBG.