The　all-fiber　passively　mode-locked　erbium-doped　femtosecond　fiber　lasers　based　on　semiconductor　saturable　absorber　mirror　(SESAM)　and　graphene　oxide　saturable　absorber　mirror　(GOSAM)　in　the　same　cavity　are　demonstrated.　The　fiber　ring　laser　is　constituted　with　1.4　m　Er3+-doped　fiber　as　gain　medium,　which　is　pumped　by　974　nm　diode　laser,　and　with　the　total　cavity　length　of　12　m.　Stable　mode-locked　laser　pulse　train　occurrs　at　29　mW　incident　pump　power　by　employing　GOSAM　as　the　saturable　absorber.　The　pulse　width　is　measured　to　be　703　fs,　and　the　center　wavelength　is　1557.67　nm,　and　3　dB　spectral　bandwidth　is　corresponding　to　3.91　nm.　However,　inserting　SESAM　with　a　modulation　depth　of　18%　in　the　configuration　mentioned　above,　we　can　obtain　ultrashort　pulse　at　32　mW　pump　power,　and　the　pulse　width　decreases　to　542　fs.　The　laser　center　wavelength　and　the　3　dB　spectral　bandwidth　are　1561.5　nm　and　5.41　nm,　respectively.　Experimental　results　show　that　the　novel　mode-locking　device-graphene　oxide　has　the　similiar　distinguished　saturable　absorber　ability.　With　its　advantages　of　low　price,　simple　preparation,　it　seems　to　be　a　good　candidate　for　saturable　absorbers　in　achieving　ultrashort　pulse　operation.　©,　2015,　Science　Press.　All　right　reserved.