Copolymerization of carbon dioxide and ethylene oxide(EO) using Co-Zn double metal cyanide complex(DMC) catalyst was carried out and the highest catalytic efficiency could be 1139 g of polymer/g of catalyst,which was higher than reported ever before.And the highest carbonate content of the copolymer could be up to 50%.It is found that catalyst concentration is the important factor in high catalytic efficiency and temperature influences carbonate content.We also studied the degradation performance of poly(ethylene oxide) in vitro.About 70 days later,almost all the copolymer degraded into carbon dioxide and polyethylene glycol with low molecular weight.