A　multiaxial　fatigue　damage　parameter　based　on　the　critical　plane　approach　was　proposed　to　calculate　the　pure　fatigue　damage　under　Uniaxial/multiaxial　loading　at　constant　high　temperatures.　For　the　fully-reversed　low-cycle　fatigue　loading　under　low　frequency　at　high　temperature,　one-half　of　the　maximum　equivalent　stress　response　value　at　cyclic　stabilization　is　used　as　the　creep　stress　to　evaluate　the　multiaxial　creep　damage.　The　linear　damage　accumulation　rule　is　used　to　predict　the　inultiaxial　creep-fatigue　life　at　high　temperature.　The　creep-fatigue　experimental　data　of　thin　tubular　specimens　with　GH4169　superalloy　and　2.25Ci-IMo　steel　were　used　to　verify　the　proposed　creep-fatigue　life　prediction　model.　The　results　showed　that　the　proposed　creep-fatigue　damage　calculation　model　can　be　used　under　either　uniaxial　or　multiaxial　nonproportional　loading　at　high　temperature.　The　proposed　model　is　used　to　predict　inultiaxial　creepfatigue　life,　and　a　good　agreement　is　demonstrated　with　experimental　data.　(c)　2006　Elsevier　Ltd.　All　rights　reserved.