Abstract We demonstrate graphene mode-locked nanosecond erbium-doped fiber laser in an all-fiber ring cavity. The clean and robust pulse train was generated at 27mW pump power. Resultant central wavelength, repetition rate and pulse width was 1560nm, 388kHz and 6ns, respectively. With two stage fiber amplifier, the output power was 553mW, corresponding to single pulse energy of 1.4μJ. In addition, the pulse-width can be varied ranging from 3ns to 20ns at repetition rate between 200kHz and 1.54MHz by changing the length of the laser cavity.