The equilibrium CO2 sorption isotherms and isobars for rubbery EVA containing various amounts of vinyl acetate (VA) over a wide pressure range 10-340 atm and 25-52 degreesC were investigated. The normalized CO2 sorption concentration (in cm(3) (STP) CO2/mole VA) isotherms of these polymers as a function of pressure consisted of two distinct regions turning at near P-c. The normalized sorption isotherms in these two distinct regions could be fairly described by two respective power laws: C = KaPna for above P-c and C = k(b)P(nb) for below P-c. The normalized CO2 sorption isotherms were found to be about the same for four EVA samples having different VA contents for below P-c, suggesting that the sorption process at below P-c, may be mainly driven by the presence of carbonyl groups. At above P-c, the degree of crystallinity of the polymer appeared to be a major factor to affect the sorption process, with the higher the degree of crystallinity, the lower the normalized CO2 sorption concentration in the polymer. The sorption isobars of the polymer as a function of temperature were governed by the interplay of density, viscosity, and diffusivity of CO2 depending on the pressure studied.