In　this　report,　a　novel　chemical　synthesis　of　polyaniline/gold　nanocomposite　is　explored　using　ionic　liquid　(IL)　1-Butyl-3-methylimidazolium　hexafluorophosphate.　The　direct　chemical　synthesis　of　polyaniline/gold　nanocomposite　was　initiated　via　the　spontaneous　oxidation　of　aniline　by　AuCl4-　in　IL.　A　nearly　uniform　dispersion　of　polyaniline/Au　particles　with　a　diameter　of　450　+/-　80　nm　was　produced　by　this　method,　which　indicates　that　this　method　is　more　suitable　for　controlling　particle　dimensions.　It　was　also　found　that　the　electrical　conductivity　of　the　polyaniline/gold　nanocomposite　was　more　than　100　times　higher　than　that　of　the　pure　polyaniline　nanoparticles.　The　polyaniline/gold　nanocomposite　displays　superior　function　in　the　biocatalytic　activation　of　microperoxidase-11　because　of　the　high　surface　area　of　the　assembly　and　the　enhanced　charge　transport　properties　of　the　composite　material.　We　also　report　the　possible　application　of　polyaniline/gold　nanocomposite　as　a　H2O2　biosensor.