Heat　transfer　performance　of　nanofluids　in　nucleate　pool　boiling　was　experimentally　investigated　on　a　horizontal　flat　surface　of　cooper　under　atmospheric　pressure.　The　surface　roughness　was　controlled　by　sandpaper　of　grade　2000#.　The　nanofluid　was　prepared　by　dispersing　the　δ-Al2O3　nanoparticle　in　the　base　fluid　refrigerant　141b(R141b)　in　0.001%,　0.01%　and　0.1%　volume　fractions.　The　results　show　that　the　heat　transfer　coefficient　increases　with　the　concentration　of　nanoparticle.　Compared　with　the　pure　fluid　R141b,　the　heat　transfer　coefficient　is　increased　50.2%　for　0.1%　volume　fraction　averagely　under　30-130　kW·m-2　heat　flux.　The　surface　deposition　of　particles　is　observed　as　one　of　the　major　factors　for　the　enhancement.　For　pure　R141b　and　low　concentration　nanofluid,　the　experimental　results　agreed　well　with　the　predictive　results　based　on　Rohsenow＇s　correlation.　The　maximum　relative　error　is　less　than　13%.　At　higher　concentrations,　the　correlation　is　no　longer　applicable.　©　All　Rights　Reserved.