Densities of CO2 + hexadecane binary mixtures were measured by the capillary high-pressure optical cell method at temperatures from 303.2 to 473.2 K and pressures up to 50.0 MPa with CO2 molar fractions x(1) = 0, 0.2555, 0.3703, 0.7348, and 0.8645. The density and excess molar volume of CO2 + hexadecane mixtures are the positive correlation function of pressure and the negative correlation function of temperature. The dissolution of CO2 increases the density of mixtures at low temperatures and decreases the density of mixtures at high temperatures. The crossover temperature increases with increasing pressure. The perturbed-chain statistical associating fluid theory (PC-SAFT) parameters of pure substances were fitted, and the densities of CO2 + hexadecane mixtures can be calculated accurately with the PC-SAFT model.