In this work, the liquid densities of n-decane/o-xylene mixtures were measured at four different component proportions, the mole fractions of n-decane are 0.2001, 0.4065, 0.5835, and 0.8041, respectively. The measurements were performed based on the high-pressure vibrating-tube densimeter, and the measured temperatures were from 283.15 K to 363.15 K and the pressures were from 0.1 MPa to 60 MPa. The Tammann-Tait equation was used to correlate the experimental densities, and the simplified Perturbed Associating Fluid Theory (sPC-SAFT) and Cubic Plus Associating (CPA) equation were used to predict the high-pressure densities of the mixtures with the binary interaction parameters. Derived properties, including isothermal compressibilities and isobaric thermal expansivities, were calculated from Tait equation, sPC-SAFT equation, and CPA equation, respectively. In addition, excess molar volumes of the considered mixtures were obtained and the effects of pressure and temperature on the excess molar volume were discussed. (C) 2019 Elsevier B.V. All rights reserved.