Efficient L-band (long wavelength band) fiber ring laser with tunable range of 43 nm (1567.1 nm～1610.1 nm) is demonstrated. Both high concentration Erbium-doped fiber and 1480 nm pump laser diode (LD) were used to depress the laser threshold pump power and to increase the slope efficiency. Output powers between 10.9 dBm and 12.1 dBm were achieved when 95 mW pump power was provided. And the signal-to-noise radio was better than 60 dB. A high slope efficiency of 0.201 was obtained at lasing wavelength of 1585 nm.