The crystallization induced by compressed CO2 was investigated for rubbery ethylene-vinyl acetate copolymer (EVA) containing various amounts of vinyl acetate (VA). The induction of crystallization was demonstrated by appearance of shoulder-like differential scanning calorimetry (DSC) endotherms at temperatures lower than T-m of polyethylene segments of EVA after CO2 treatments. The intensity of the endothermic shoulders and the degree of crystallinity increased with increasing VA content, suggesting that the interaction of CO2-carbonyl groups governed the induction of crystallization of EVA upon CO2 treatment. The interaction of CO2-carbonyl group was found to decrease with increasing temperature as demonstrated by the decreased crystallization enhancement for 37 degreesC as compared with that for 32 degreesC. The enhancement of crystallization did not monotonically increase with increasing CO2 pressure, resulting from the interplay of thermodynamic and kinetic driving forces, both being associated with the CO2 pressure and thus the sorption concentration.