Polarization characteristics of Rayleigh backscattered light in erbium-doped optical fiber amplifiers are investigated by using 1.54-?m signal light pumped by 1.48-?m light. The Rayleigh backscattered equivalent reflectance for the signal light was ? 49.9 dB in a 30-m-length erbium-doped fiber and was increased and was amplified with the pump light. Linear polarization in the input signal light was almost preserved in the Rayleigh backscattered light in the absence of pumping. The degree of polarization was degraded from 88% to 52% with an increase in the pump power.