High-pressure phase behavior measurements of (CO2 + heptadecafluoro-1-decene) and (CO2 + nonafluoro-1-hexene) binary mixture systems were carried out using a variable volume view cell. The experimental range of temperature and pressure are from 313.2 K to 343.2 K and up to 15 MPa, respectively. The correlation was performed using the Peng-Robinson equation of state and the van der Waals one-fluid mixing rule. The critical constants, T-c and P-c, were estimated by the several group contribution methods. The acentric factor was estimated by the Lee-Kesler method.