In petroleum industry injection of carbon dioxide has a lot of economical advantages for oil recovery. The diffusion coefficient of CO2 in oil-saturated porous media is a critical parameter. However, there is no universally applicable technique for measuring the diffusion coefficients of gas in oil-saturated porous media. The main objective of this work is to develop a possible experimental method for measuring CO2 diffusion coefficients in oil-saturated porous media by CT technique. At last the relationship between pressure and diffusivity at T= 29 °C is discussed.