Due to their stability，polyaniline (PAn) is considered to be one of the most potential applicable conducting polymer．Ion beam effects on polyaniline films un-der the ion implantation with potassium ions (K+) have been investigated by studying P An in pernigraniline form through the FTIR and the temperature depen-dence of the dc conductivity．The pristine pernigraniline forill PAn has conductivi-ty as low as～10-14S／cm2．The energy of K+ ions is 40 keV，while the dose ranged from 1×1015 to 1×1017K+／cm2．Results showed that the conductivity of the PA films enhanced when doses increased．The conductivitv at implanted region of the PAn films approaches 3.3×10-6S／cm when dose is about 1×1017K+/cm2，and is eight magnitudes higher then that of the pristine．FTIR spectra demonstrated that the pernigraniline PAn reveals reduction under the K+ ion implantation

which is proposed to be the reason of conductivity．The mechanism of ion implantation and the relation of temperature dependence of conductivity σ～exp[-(T0／T)1/2] suggested that the conductivity is due to the hopping in granular metals island．