In this paper，super-hydrophobic polyaniline with hierarchical structure has been synthesized via a “soft template chemical oxidation” method with aniline as monomer，ammonium persulfate as oxidant in the solution of perfluorocaprylic acid (PFOA).The morphologies and structures of the polyaniline were further proved by SEM，FT-IR，XRD and UV-vis.When ［PFOA］ = 0.002 4 mol/L，［ANI］ = 0.022 mol/L，T =25 ℃，［APS］ = ［ANI］，the synthesized PANI was a sheet structure about tens of micrometers in length and 2~5 μm in width，in which the surface of sheet structure was composed of PANI fiber (about 1 μm in length with a diameter ca.100 nm).When ［ANI］= 0.044 mol/L，the synthesized PANI was a sheet structure of about 20 μm in length and 2~3 μm in width，in which the surface was covered with short thick irregular fibers.The water contact angles of both structures were 149° and 151°，respectively.These results demonstrate that the as-prepared PANIs exhibit excellent hydrophobic properties.