Using the reduced graphene oxide (rGO) as a saturable absorber (SA) in an Er-doped fiber (EDF) laser cavity,we obtain the Q-switching operation.The rGO SA is prepared by depositing the GO on fluorine mica (FM) using the thermal reduction method.The modulation depth of rGO/FM is measured to be 3.2％.By incorporating the rGO/FM film into the EDF laser cavity,we obtain stable Q-switched pulses.The shortest pulse duration is 3.53μs,and the maximum single pulse energy is 48.19nJ.The long-term stability of working is well exhibited.The experimental results show that the rGO possesses potential photonics applications.