Since　a　high　electron　density　of　Au　surfaces　can　be　conducive　to　the　oxidation　of　CO　over　the　supported　Au　nanoparticles,　the　conductive　polymer　polyaniline　(PANI)　was　assembled　into　Au/TiO2　to　prepare　a　Au/TiO2-PANI　catalyst　for　oxidizing　CO.　It　is　found　that　PANI　could　be　well　wedged　with　Au/TiO2,　which　remarkably　promoted　the　oxidation　of　CO　over　the　TiO2　supported　Au　nanoparticles　at　room　temperature.　Moreover,　the　presence　of　a　trace　amount　of　H2O　could　promote　the　oxidation　of　CO　over　the　Au/TiO2-PANI　catalyst.　Based　on　the　testing　results　of　structure　characteristic,　electrochemical　impedance　and　adsorbing　CO　of　Au/TiO2-PANI,　it　was　proposed　that　the　PANI　could　be　acted　as　an　electron　transmitter　to　promote　the　electron　transfer　from　TiO2　to　Au,　resulting　in　the　increase　of　surface　electron　density　of　Au　sites　and　then　the　promoted　activation　of　CO　adsorbed　at　Au　sites.　(C)　2014　Elsevier　B.V.　All　rights　reserved.