An experimental study of heat transfer characteristics of flow boiling of R410A-oil mixture in an enhanced tube was performed to investigate the influence of mass flux，vapor quality and oil concentration on heat transfer coefficient.The test tube was internally spiral grooved tube，the length of the test tube was 2000 mm，and the outside diameter was 7.0 mm.The test results showed that the heat transfer coefficient of R410A initially increased with vapor quality and then decreased，presenting a local maximum in the vapor quality range between 0.7 and 0.8.The presence of oil enhanced heat transfer coefficient when vapor quality was less than 0.5.When vapor quality was higher than 0.6，heat transfer coefficient decreased rapidly with increasing nominal oil concentration and vapor quality.A new heat transfer coefficient correlation of flow boiling of R410A-oil mixture inside 7 mm enhanced tube was developed based on the mixture properties，and it agreed with 89% of experimental data within deviation of ±30%，and the mean deviation was 17.3%.