Stimulated Brillouin scattering (SBS) threshold and frequency shift of single-mode fiber are studied under different temperatures. Based on the theory of SBS, the relation of SBS threshold and frequency shift with temperature is analyzed. Experimental system is designed and built, and SBS spectrum and threshold of 2 km single-mode fiber are measured under different temperatures. The experiments indicate that the Brillouin frequency shift increases linearly with the increasing temperature. Low temperature can suppress Stokes lights. The lower the temperature is, the higher SBS threshold is. Temperature has a direct effect on the SBS of fiber.