The measurements of PvTx properties of HFO-1234yf/HFC-32 binary mixture in the vapor phase were carried out by single-sinker magnetic suspension densimeter in the range of temperatures from 279.8 to 347.9 K, pressures from 0.10 to 2.66 MPa, densities from 230 to 66.02 kg m(-3), and mole fractions of HFO-1234yf from 0.062 to 0.610. The experimental expanded uncertainty (k = 2) in temperature, pressure, and mole fraction are estimated to be 12 mK, 1.4 kPa, and 0.0002, respectively. The relative expanded uncertainty (k = 2) in density is 0.029-0.104%. On the basis of the experimental PvTx properties data, a truncated virial equation of state was developed for the binary HFO-1234yf/HFC-32 system. It reproduces the experimental values with average absolute deviations of 0.10% and 0.11% for pressure and density, respectively. (C) 2018 Elsevier B.V. All rights reserved.