Solvent activation of Mg(OEt)(2) in ethanol with carbon dioxide was carried out in a 1-L three-neck flask under nitrogen atmosphere, to investigate structural changes of Mg(OEt)(2) support. During activation of Mg(OEt)(2) by ethanol and CO2, a suspension mixture was converted to a clear solution and CO2 was inserted into the Mg-O bond of Mg(OEt)(2), to form magnesium ethyl carbonate. The solid supports were obtained from the removal of solvents by heating, during which CO2 split off from the magnesium ethyl carbonate between 100 and 150 degreesC. The structural changes of the obtained supports and the corresponding catalysts were checked by IR and TGA. The polymerization behavior of propylene with the catalyst and morphology of the obtained polymer were also examined.