The　Au/Fe2O3　catalyst　was　prepared　by　the　microemulsion　method　in　two　inverse　microemulsions,　Triton　X-100/n-hexanol/cyclohexane/(aqueous　metal　salt　solution)　and　cetyltrimethylammonium　bromide　(CTAB)/n-hexanol/(aqueous　metal　salt　solution),　respectively.　Surfactant,　oil　and　aqueous　solution　of　HAuCl4　and　Fe(NO3)3　were　mixed　to　form　a　homogeneous　microemulsion.　Then,　the　Au/Fe2O3　catalyst　was　prepared　by　mixing　the　microemulsion　and　ammonia　solution.　All　the　synthesis　parameters　had　remarkable　effects　on　the　catalyst　activity.　The　catalyst　sample　calcined　at　250°C　had　the　highest　activity;　the　sample　prepared　by　the　microemulsion　consisting　of　nonionic　surfactant　(Triton　X-100)　showed　a　higher　activity　than　that　from　cationic　surfactant　(CTAB).　CO　conversion　reached　99.5%　at　Au　loading　of　3%　and　200°C.