In　the　current　study,　a　coupled　thermo-mechanical　constitutive　model　of　concrete　was　newly　developed　to　characterize　the　mechanical　responses　of　concrete　at　different　temperatures　within　thermodynamics　framework.　The　coupling　thermo-mechanical　contributions　among　thermal　effect　(up　to　800　degrees　C),　damage　evolution　and　thermo-plastic　hardening　were　creatively　taken　into　account　in　energy　potential　function.　The　thermal　damage　evolution　law　and　load　induced　plastic　mechanical　damage　evolution　law　was　developed　respectively　and　were　coupled　in　the　dissipation　function.　The　thermo-mechanical　hardening　rule　was　considered　through　adopting　back　stress　and　hardening　parameters.　A　particular　advantage　of　the　proposed　model　is　that　fiber　influence　coefficients　can　be　employed　in　potential　functions　to　upgrade　for　modeling　fiber　reinforced　concrete.　The　impact　of　types　and　volume　fractions　of　fibers　on　the　reinforcement　mechanism　was　calculated　in　the　fiber　influence　coefficients.　Besides,　an　orthotropic　triaxial　compression　model　was　developed　for　concrete　and　fiber　reinforced　concrete　to　predict　multiaxial　stress　behavior　at　high　temperature.　The　proposed　model　was　coded　and　implemented　into　the　Fortran　program　and　the　nonlinear　behaviors　of　concrete　and　fiber　reinforced　concrete　were　predicted.　Good　effectiveness　and　accuracy　have　been　validated　through　comparing　the　modelling　results　and　six　groups　experimental　results　in　literatures,　which　illustrates　that　the　proposed　model　is　robust　and　reliable.　Finally,　a　discussed　study　was　conducted　to　investigate　the　effect　of　hardening　parameters　and　thermal　effect　on　the　yield　surface.