In　engineering　practice,　refrigerant　contains　lubricating　oil　form　compressor　in　the　refrigerating　system.　In　this　study,　the　impact　of　different　oil　contents　on　evaporation　of　falling　film　on　horizontal　enhanced　tube　was　discussed.　Experiments　were　conducted　for　R134a　at　the　saturation　temperature　of　6　on　enhanced　copper　tube,　with　oil　contents　being　0.5%,　1.2%　and　5.1%,　respectively,　and　heat　fluxes　ranging　from　30　kW/m2　to　65　kW/m2,　sprinkle　densities　being　0.13,　0.17,　and　0.21,　kg/(s·m).　The　experimental　results　show　that　heat　transfer　coefficient　of　the　outside　horizontal　enhanced　tube　increases　with　both　oil　contents　growing　from　0.5%　to　5.1%　and　increasing　sprinkle　densities.　However,　with　the　augments　of　oil　contents,　the　increases　of　heat　transfer　coefficient　are　nearly　insensitive　to　the　increasing　sprinkle　densities.　In　certain　range　of　content,　lubricating　oil　can　improve　heat　transfer　coefficient　of　R134a　falling　film　evaporation.　©,　2015,　Tianjin　University.　All　right　reserved.