Time　dependent　fatigue　damage　model　under　cyclic　loading　was　proposed　by　considering　the　effect　of　creep　and　oxidation　at　high　temperature　on　the　fatigue　damage.　The　high　temperature　fatigue　damage　without　holding　time　was　divided　into　pure　fatigue　damage,　damage　caused　by　the　time　dependent　factors　and　interactive　damage　to　combine　effect　of　high　temperature　to　fatigue　damage　with　the　damage　rule.　The　converting　time　influenced　by　high　temperature　was　proposed　according　to　tension-compression　strain　rate　and　different　cycle　period　based　on　the　SEM(scanning　electron　microscope)　observation　of　the　fatigue　rupture　surface　and　fatigue　process.　The　results　for　2.25Cr-1Mo　steel　tests　under　uniaxial　and　multiaxial　high　temperature　fatigue　showed　an　error　within　a　factor　of　two.