A new correlation for forced convection vaporization heat transfer of no n-azeotropic refrigerant mixtures inside a horizontal tube is developed. It is simple but accurate. For the calculation of 142data points, 90. 14% of them are within the relative deviation of 10%. The maximum deviation is 23 .67%. Methods of determiming the thermodynamic and transport properties of non-azeotropic refrigerant mixtures are introduced. According to the calculation and analysis, a conclusion is reached that the effect of mass transfer resistance on heat transfer is negligible under the condition of forced convection vaporization.