The catalysts of supported potassium iodide were produced using dip method. The catalytic activity were evaluated by the reaction of carbon dioxide, propylene epoxide and glycerol to synthesize glycerol carbonate and KI/γ-Al2O3 was found to be the best one, where the conversion of glycerol was 58.5% and the yield of glycerol carbonate was 54.6%. Different specific surface area of γ-Al2O3 had some effect on KI loading of active component. KI/γ-Al2O3 catalysts were characterized by BET and XRD, which showed that γ-Al2O3 supporter with high specific surface was beneficial to dispersion of KI. At the same time, the effects of reaction temperature, molar ratio of reactants and KI loading on the reaction were investigated and the optimal experimental parameters were obtained. Through repeated using tests, the result showed that the catalysts of KI/γ-Al2O3 had good stability.