The characteristics of L-band erbium doped fiber are investigated by numerical simulation and experiment. Gain spectrum is flat on optimum population inversion level (-40% ). High gain ( >36 dB) and low noise ?.4 dB) are achieved with dual-stage configuration. The flattened amplification bandwidth is 33.5 nm ( ± 0.5 dB) (1569 -1602.5 nm) without gain equalized filter (GEF).