The Waterborne cationic perfluorinated acrylate soap-free emulsionwas prepared using perfluorinated alkyl ethyl acrylate (FM), methyl methacrylate (MMA), butyl acrylate (BA), octadecyl acrylate (ODA), methacryloxyethyl trimethylammonium chloride(DMC) as monomers, azobisisobutyronitrile (AIBN) as initiator and hydroxyl ethyl acrylate (HEA) as crosslinker. The structure of the copolymer was characterized in many ways. The contact angle of water and liquid paraffin on the fabric treated by the emulsion was 138癮nd 125皉espectively. The surface free energy of membrane was 19.01mJ/m2 when w(FM)=50%. The structure of fluorinated membrane surface appeared Lotus-Effect.