The solubility of CO2 in NaCl solutions with mass fractions of 0.01 to 0.03 was measured at (30 to 60) degreesC and (10 to 20) MPa. The CO2 was dissolved in NaCl solution in a pressurized vessel, and a sample of the saturated solution was removed from the vessel. The solubility was then estimated by measuring the mass of the sample and the pressure of the dissolved gas. On the basis of this experimental data, an equation for predicting the CO2 mole fraction x, in NaCl solution as a function of temperature t = (30 to 60) degreesC, pressure P = (10 to 20) MPa, and mass fraction, S, of NaCl = (0.01 to 0.03) was determined. H(P,T,S)/MPa = 36.1P/MPa + 3.87T/K - 1097.1 + (196P/MPa + 26.9T/K - 8810)S, where H is Henry's coefficient, H = P-c/x(1), P-c is the partial pressure of carbon dioxide, T is the absolute temperature, and S is the mass fraction of NaCl in the aqueous solution.