The present invention relates to an optical transmission line enabling Raman amplification of an optical signal when pumping light is supplied thereto, a method of making this optical transmission line, and an optical transmission system using this optical transmission line. This optical transmission line is an optical transmission line enabling Raman amplification of an optical signal when pumping light is supplied thereto, wherein a region yielding the maximum value of Raman gain coefficient is separated from an end portion where the pumping light is supplied by a predetermined distance along a direction in which the pumping light advances. This optical transmission line can restrain the power of optical signal, at any point of the optical transmission line, from increasing to such an extent that optical Kerr effects occurs remarkably and from decreasing to such an extent that the SN ratio deteriorates greatly, and can fully secure the power of optical signal at the end point of the optical transmission line.