Transition　metal　oxides　are　easy　to　form　insoluble　oligomer　in　reaction　because　of　complicated　oxidation　states,　so　it　is　difficult　to　obtain　the　desired　mesoporous　structure.　To　resolve　the　problem,　mesoporous　iron　oxide　was　synthesized　by　reacting　a　micellar　phase　of　sodium　dodecyl　sulfate　(SDS)　with　iron　polymer　solution　which　was　prepared　by　controlling　the　proportion　of　sodium　hydroxide　and　ferric　chloride.　Crystal　structure　and　surface　structure　of　the　mesoporous　iron　oxide　was　characterized　by　powder　X-ray　diffraction　(XRD),　Fourier　transform-infrared　spectroscopy　(FT-IR),　thermogravimetric　analyse(TGA),　Nitrogen　adsorption-desorption　method　and　so　on.　The　results　show　that　mesoporous　α-Fe2O3　can　be　obtained　after　calcining　at　450°C　with　OH-/Fe3+　ratio　of　2.0.　Its　surface　area　is　146.5　m2·g-1,　BJH　average　diameter　is　6.9　nm,　pore　volume　is　0.27　cm3·g-1.　The　as-prepared　mesoporous　iron　oxide　has　better　thermal　stability,　it　still　has　surface　area　of　110.2　m　2·g-1　after　calcination　at　550°C.