In　this　work,　an　organic　Rankine　cycle　(ORC)　with　internal　heat　regeneration　(referring　to　regenerative　ORC)　is　designed　and　built,　which　uses　refrigerant　R123　as　working　fluid.　Based　on　this　experimental　system,　we　test　the　performances　of　the　ORCs　with　and　without　internal　heat　regeneration　at　different　operating　conditions.　The　result　shows　that　when　the　heat　source　temperature　is　100°C,　the　cycle　efficiency　are,　respectively,　5.98%　and　4.71%　for　the　RORC　and　ORC　although　the　output　powers　of　both　cycles　are　nearly　the　same　which　is　about　510　W.　The　influences　of　four　key　parameters　including　the　refrigerant　charge,　refrigerant　flow,　evaporating　temperature　and　condensing　temperature　on　the　cycle　performance　are　experimentally　explored.　It　is　indicated　that　there　exists　an　optimal　refrigerant　charge　of　about　14.19　kg　to　result　in　the　maximum　output　power.　In　addition,　it　is　found　that　under　the　high　torque,　increasing　the　working　fluid　flow　rate　leads　to　the　increase　in　the　cycle　performance.　Under　the　low　torque,　however,　lowering　the　flow　rate　can　result　in　the　increase　in　the　cycle　performance.　Further,　it　is　shown　that　the　output　performance　of　the　system　is　increased　with　increasing　the　evaporating　temperature.　However,　it　is　noticed　that　as　the　evaporating　temperature　rises,　the　influence　of　evaporating　temperature　on　the　output　power　fades　out.　Condensing　temperature　has　no　significant　effect　on　the　stability　of　the　system.