A wide band erbium-doped fiber amplifier with a gain enhancement is provided comprising a first fiber amplifier adapted to amplify C-band components of an input optical signal, a second fiber amplifier connected to the first fiber amplifier in series while being disposed downstream from the first fiber amplifier to amplify L-band components of the input optical signal. A C/L splitter is disposed between the first and second fiber amplifiers and to split the amplified C and L-band optical signals to flow along different paths. A fiber reflector is disposed downstream from the second fiber amplifier to reflect the amplified L-band optical signal to flow backwards toward the second fiber amplifier. A circulator is disposed between the C/L splitter and the second fiber amplifier to guide the amplified L-band optical signal, reflected to flow backwards by the fiber reflector, so that the amplified L-band optical signal flows along a path different from that of optical signals applied to the circulator. A C/L combiner combines the amplified C-band optical signal split by the C/L splitter with the amplified L-band optical signal guided by the circulator, and applies the resultant optical signal to an output stage.