This paper studies the Brillouin shift variations of fibers in Optical Fiber Composite Overhead Ground Wire（OPGW）cables by using the BOTDR technology on the basis of the Brillouin scattering principle.The experimental results show that the temperature coefficients of Brillouin Scattering（BS）shifts of different fibers in the same cable are slightly different from those of the basic frequency shifts

while there is a fairly constant difference in temperature coefficients between fibers in the sunshine zones and those in the shadowy zones.