Dependence of stimulated Brillouin scattering (SBS) on the temperature distribution applied periodically to a polarization-maintaining fiber is investigated. The SBS intensity decreases with an-increase in the temperature difference. SBS disappears at 37 degrees C temperature difference, where 10 mW pumping light of 1.319 mu m wavelength is launched into the fiber of 1.6 km length. The SBS threshold increases as the temperature difference increases.