Hydrate equilibrium conditions (vapor + hydrate + liquid water + liquid tetrahydrofuran, THF) formed from carbon dioxide in aqueous solutions of THF is determined using a stepwise heating method under isochoric conditions in this work. THF is reported to form an SII hydrate. Hydrate phase equilibrium conditions are measured under the conditions of the THF mass concentration range of 0.0726-0.2503 and pressure range of 0.10-1.87 MPa. The experimental results present that the equilibrium pressures of the experimental systems of carbon dioxide + THF + H2O are obviously lower than that of the carbon dioxide + H2O system under test conditions. Furthermore, the experimental results also indicate that the carbon dioxide hydrate formation pressure decreased more apparently with more additives of THF.