The graphene-based passively Q-switched erbium-doped fiber laser is reported.The laser adopts ring cavity configuration

and the Q-switcher is the self-made graphene absorber.Stable Q-switcher pulse train occurs at about 0.8mW incident pump power and the pulse repetition rate is 31 kHz.The maximum average output power of 13.8mW is obtained when pump power rise to 460 mW with corresponding pulse width of 800 ns

repetition rate of 77 kHz

and central wavelength of1 558 nm.Furthermore

we also explain the phenomenon that the repetition rate

average output power and incident pump power having approximate linear relationship.