In this paper, phase equilibrium data of the double tetrabutylammonium chloride (TBACl: C16H36ClN) semidathrate hydrate with a guest gas (CO2 or N-2) at four different TBACl concentrations (0.06, 0.15, 0.34, and 0.44 mass fraction) were experimentally measured by employing an isochoric pressure-search method in the temperature range of (282.9 to 293.2) K and at pressures up to 13.57 MPa, respectively. The results demonstrated that double TBACl + CO2 (or N-2) semidathrate hydrates had an obvious advantage in thermal stability compared to pure CO2 (or N-2) hydrates. And the strongest stabilization effect was observed with the application of TBACl at 0.34 mass fraction, corresponding to TBACl center dot 30H(2)O. In addition, the results were compared with the corresponding data reported in open literature. The comparisons showed that some literature data seemed to be not reliable.