An optical amplification repeating transmission system ( alpha ) in which an optical signal damped in each of optical fibers (9) as transmission lines while being transmitted through it is amplified and repeated by each of optical amplification repeaters (A') sequentially without being converted into an electric signal, so that the optical signal is transmitted from an optical transmission terminal station (10) to another one (11) opposed thereto. The system ( alpha ) is characterized in that the mean value of the widths of the fluctuations in the gains of the repeaters (A'), which are due to the dependence of the gains on the state of polarization of the optical signal to the repeaters (A'), is limited to 0.2 dB or less. <IMAGE>
