An experimental study of the pressure-volume-temperature-composition pVTx properties for binary mixtures of HFC- 32(CH2F2) and HFC-125(C2HF5) was conducted in the range of temperatures from 343 to 423 K, pressures from 4.0 to 15.6 MPa, densities from 485 to 491 kg·m−3, and compositions from 0.05 to 0.90 mole fraction of HFC-32, with uncertainties of 4.4 mK, 1.6 kPa, 0.02% , and 0.0004 mole fraction, respectively. The available experimental data for pVTx properties of binary mixtures of HFC-32 and HFC-125 have been compared with the equation of state developed by Tillner-Roth et al. From the critical evaluation, this equation of state should be revised in the range of low mole fractions of HFC-32.