The　hydroxyl-Fe　pillared　montmorillonite　complexes　at　different　OH/Fe　molar　ratios　(i.e.,　0.6,　0.8,　1.0,　1.5　and　2.0　OH/Fe　montmorillonite)　were　prepared　with　purified　montmorillonite　samples　(K10)　as　raw　materials.　The　adsorption　interaction　of　aminoglycoside　antibiotics　with　both　OH/Fe　montmorillonite　and　K10　were　investigated　at　various　pH　values　of　sorption　solution　and　time　on　the　adsorption　of　the　OH/Fe.　The　adsorption　materials　were　analyzed　by　X-ray　diffraction,Fourier　transformed　infrared　spectoscopy　and　X-ray　photoelectron　spectroscopy,　respectively.　The　results　show　that　the　order　of　gentamicin　equilibrium　sorption　amount　of　OH/Fe　from　low　to　high　is　K10(33.3　mg/g),　0.6OH/Fe(43.4　mg/g),　0.8　OH/Fe(44.8　mg/g),　1.0　OH/Fe(56.0　mg/g),　2.0　OH/Fe(64.8　mg/g),　1.5　OH/Fe(71.9　mg/g).　The　1.5　OH/Fe　has　the　maximum　adsorption　capacity,　which　is　2　times　greater　than　that　of　K10.　The　Freundlich　model　can　well　fit　the　adsorption　isotherms　of　gentamicin　by　both　OH/Fe　and　K10.　It　is　indicated　that　the　adsorption　capacity　of　gentamicin　can　reach　the　equilibrium　after　3　h,　that　the　adsorption　capacity　of　gentamicin　on　pillared　montmorillonite　increases　with　the　increase　of　pH　value,　which　can　be　described　by　the　pseudo　second-order　kinetic　equation.　The　analysis　of　adsorption　mechanism　shows　that　the　adsorption　capacity　of　OH/Fe　increase　mainly　due　to　the　increase　of　the　interlayer　distance　of　montmorillonite　pillared,　and　that　cation　exchange　is　the　dominant　mechanism　of　gentamicin　entering　montmorillonite　interlayer,　and　the　chemical　adsorption　of　surface　complexing　is　also　one　of　the　adsorption　mechanisms.　The　adsorption　of　gentamicin　into　hydroxyl-Fe　pillared　montmorillonite　can　cause　the　collapse　of　structure　and　the　decrease　of　interlayer　region.　©　2016,　Chinese　Ceramic　Society.　All　right　reserved.