In this work, the cycloaddition reactions of CO2 with various epoxides to form five-membered cyclic carbonates catalyzedbyanefficient amino acidbased biocompatible catalyst were investigated. It was found that the activity of amino acid could be obviously enhanced in the presence of alkali metal salts, and the L-tryptophan catalyticsystem was the mostefficient among the catalysts employed. Based on the result, a possible mechanism for the synergetic effect of catalyst was proposed.The process reported here represents a simple, ecologically safer, cost-effective route to cyclic carbonates with high product quality, as well as easy catalyst recycling.