The　organic　Rankine　cycle　(ORC)　is　a　popular　and　promising　technology　that　has　been　widely　studied　and　adopted　in　renewable　and　sustainable　energy　utilization　and　low-grade　waste　heat　recovery.　The　use　of　zeotropic　mixtures　in　ORC　has　been　attracting　more　and　more　attention　because　of　the　possibility　to　match　the　temperature　profile　of　the　heat　source　by　non-isothermal　phase　change,　which　reduces　the　irreversibility　in　the　evaporator　and　the　condenser.　The　selection　of　working　fluid　and　expander　is　strongly　interconnected.　As　a　novel　expander,　a　single　screw　expander　was　selected　and　used　in　this　paper　for　efficient　utilization　of　the　wet　zeotropic　mixtures　listed　in　REFPROP　9.1　in　a　low-temperature　subcritical　ORC　system.　Five　indicators,　namely　net　work,　thermal　efficiency,　heat　exchange　load　of　condenser,　temperature　glide　in　evaporator,　and　temperature　glide　in　condenser,　were　used　to　analyze　the　performance　of　an　ORC　system　with　wet　and　isentropic　zeotropic　mixtures　as　working　fluids.　The　calculation　and　analysis　results　indicate　that　R441A　with　an　expander　outlet　temperature　of　320　K　may　be　the　suitable　zeotropic　mixture　used　for　both　open　and　close　type　heat　source.　R436B　may　be　selected　with　an　expander　outlet　temperature　of　315　K.　R432A　may　be　selected　with　an　expander　outlet　temperature　from　295　K　to　310　K.