The main part of this book consists of tables of the equilibrium thermodynamic properties of oxygen for both the gas and liquid phases and along the saturation curve and the melting curve. The limits of the tables are 54k to 300k for pressures up to 80MPa. The properties listed are volume, entropy, enthalpy, isobaric heat capacity, compression factor, fugacity-pressure ratio, Joule-Thomson coefficient, ratio of heat capacities and speed of sound as functions of pressure and temperature; and pressure, entropy, internal energy and isochoric heat capacity as functions of density and temperature. The text gives a critical assessment of the accuracy of all the available experimental data and gives comparisons of the tables with the experimental data. The equations which were used to prepare the tables are given in a form suitable for computer programming.