In　this　paper,　an　exploration　of　the　practical　thermodynamic　performance　limits　of　the　organic　Rankine　cycle　(ORC)　under　working　fluid　and　cycle　parameter　restrictions　is　presented.　These　performance　limits　are　more　realistic　benchmarks　for　the　thermodynamic　cycle　than　the　efficiency　of　the　Carnot　cycle.　Subcritical　ORC　configuration　with　four　typical　case　studies　that　are　related　to　temperature　ranging　from　373.15　to　673.15　K　is　taken　into　account.　The　ORC　is　defined　by　its　cycle　parameters　and　working　fluid　characteristic　properties.　The　cycle　parameters　involve　evaporation　temperature　(T-eva),　condensation　temperature　(T-con)　and　superheat　degree　(Delta　T-sup),　while　the　working　fluids　are　represented　by　the　characteristic　properties　including　critical　temperature　(T-c),　critical　pressure　(p(c)),　acentric　factor　(omega),　and　molar　ideal　gas　isobaric　heat　capacity　based　on　the　principle　of　corresponding　states.　Subsequently,　Pareto　optimum　solutions　for　obtained　hypothetical　working　fluids　and　cycle　parameters　are　achieved　using　multi-objective　optimization　method　with　the　consideration　of　both　thermal　efficiency　(eta(th))　and　volumetric　power　output　(VPO).　Finally,　sensitivity　analysis　of　the　working　fluid　characteristic　properties　is　conducted,　and　the　second　law　of　thermodynamics　analysis,　especially　the　applicability　of　entropy　generation　minimization,　is　performed.　The　results　show　that　the　current　commonly　used　working　fluids　are　widely　scattered　below　the　Pareto　front　that　represents　the　tradeoff　between　eta(th)　and　VPO　for　obtained　hypothetical　fluids.　T-eva　and　T-con　are　the　most　dominant　cycle　parameters,　while　T-c　and　omega　tend　to　be　the　most　dominant　characteristic　property　parameters.　The　entropy　generation　minimization　does　not　give　the　same　optimal　results.