The　thermal　fatigue　damage　of　recrystallization　tungsten　with　different　cycle　times　was　studied　at　power　of　141.5　MW/m(2)　by　electron　beam　thermal　fatigue　test　system　which　was　built　independently　in　the　laboratory.　Changes　in　surface　topography　after　thermal　shock　in　many　cycles　were　observed　by　scanning　electron　microscopy　(SEM).　Changes　of　three-dimensional　morphology　and　surface　roughness　were　detected　by　Atomic　force　microscope　(AFM)　and　the　surface　hardness　was　tested　after　thermal　fatigue.　The　results　show　that　with　the　increase　of　the　cyclic　number,　thermal　fatigue　damage　intensifies.　The　surface　of　tungsten　starts　to　be　molten　at　1000　cycles.　The　surface　roughness　changes　linearly　with　the　cycle　number;　it　is　increased　firstly　and　then　decreased　because　of　the　fatigue　hardening.