The surface tension of difluoromethane (R-32) (1) + 1,1,1,2,3,3,3-heptafluoropropane (R-227ea) (2) binary mixtures was measured at five nominal mass fractions of w(1)' = 0.3083, 0.3639, 0.4064, 0.5519, and 0.7345 over the temperature range from (253 to 333) K using the differential capillary rise method (DCRM) under vapor-liquid equilibrium conditions. The temperature and surface tension uncertainties were estimated to be within +/-10 mK and +/-0.15 mN(.)m(-1), respectively. A new correlation based on the mass fraction was developed to represent the surface tension in the R-32 + R-227ea system.