Abstract: With the advantages of non-toxicity，non-flammability，cheapness and mild critical point conditions，carbon dioxide（CO2）has become the most adequately studied supercritical fluid medium that is widely used in extraction，chemical reaction，material preparation etc. as a favored alternative to conventional solvent. This review summarizes the utilization of CO2 in organic synthesis both as a reagent and as a medium in recent years，especially，as starting materials to prepare organic carbonates，organic acids，phenolic acid，formic acid and their derivatives.