Hexafluoropropylene oxide(HFPO) is a representative oxygen-containing C3 fluoromonomer, which enhances physical and chemical properties of fluoro copolymers. It is also essentially used for manufacturing fluorinated ion-exchange membranes such as Nafion®. HFPO was successfully obtained from a liquid-phase epoxidation of hexafluoropropylene with active oxygen species such as NaOCl and H2O2. Addition of transition metal halides to the HFP epoxidation was revealed to appreciably enhance the yield of HFPO. Among the transition metal halides used, ferric chloride showed the highest catalytic activity in the epoxidation reactions with both NaOCl and H2O2.