Mode-locked erbium doped fiber laser by using graphene oxide (GO) that obtained by oxidation and ultra-sonification process of natural graphite was reported. GO produced was dissolved in water and mixed with Polyethylene Oxide (PEO) to form film. When the fabricated GO-PEO film saturable was employed in the proposed EDFL configuration, the laser generates 1.25 ps pulses at a repetition rate of 21.8 MHz with pump input of 70 mW. The stable mode-locking operation was observed within pump input power of 70 mW until 175 mW. Soliton-like spectrum was achieved with prominent Kelly-sideband and centre wavelength of 1558.6 nm.