Phase equilibria for the CH4 + CO2 + H2O system have been investigated in the past, but mole fraction of methane and carbon dioxide in the bulk liquid phase has not been measured under hydrate-liquid-vapor equilibrium. Equilibrium liquid composition is very important as it defines the driving force for hydrate growth. This study presents the solubility of methane and carbon dioxide under H-Lw-V equilibrium. Emphasis is made on the effect of pressure along the respective isotherms on the equilibrium mole fraction of the individual hydrate formers in the liquid. (C) 2010 Elsevier B.V. All rights reserved.