Q-switched　Yb-doped　fiber　lasers　based　on　few-layer　WS2　and　mono-layer　WS2　were　demonstrated　in　this　paper.　The　modulation　depths　of　few-layer　WS2-polyvinyl　alcohol　film　and　mono-layer　WS2-polyvinyl　alcohol　film　were　21.1%　and　25.9%,　respectively.　The　shortest　pulse　durations　of　the　two　fiber　lasers　were　2.7　mu　s　and　748　ns,　respectively,　and　the　maximum　pulse　energy　was　205　nJ　and　154.2　nJ.　From　the　results,　the　pulse　duration　of　the　fiber　laser　with　mono-layer　WS2　is　narrower　than　that　of　the　laser　with　few-layer　WS2,　and　the　peak　power　of　the　pulse　is　higher　than　that　of　the　laser　employing　few-layer　WS2　owing　to　the　large　modulation　depth　of　mono-layer　WS2.　To　the　best　of　our　knowledge,　205　nJ　is　the　largest　pulse　energy　of　Q-switched　fiber　lasers　with　TMDs　at　1.0　mu　m　waveband.　The　results　illustrate　that　WS2　is　one　promising　saturable　absorber　to　achieve　high　energy　output　in　fiber　lasers.