We made an primary investigation on the plasma copolymerization of hexafluoropropene, ethylene and styrene. Through measurement of IR and GC-MS we concluded that although electron energy of the plasma system was high enough to break common chemical bond, the plasma copolymerization just as usual radical copolymerization must follow that the activity of copolymerized monomers need approach each other, or else the high active monomer would polymerize to anticipate copolymerization.