Montmorillonite　(Mt)/carbon　foam　nanocomposites　were　prepared　by　direct　carbonization　of　organic　montmorilonite　(OMt)/bismaleimide　(BMI)　resin　mixtures　at　ambient　pressure.　Carbonization　behaviors　of　the　OMt/BMI　resin　mixtures　were　studied　using　X-ray　diffraction　(XRD)　and　thermogravimetric　analysis　(TGA).　In　addition,　the　influences　of　the　additive　amount　of　OMt　on　the　microstructures,　physical　properties　and　compressive　behaviors　and　oxidation　resistance　of　the　resulting　nanocomposites　were　investigated.　Results　show　that　with　the　increasing　of　the　additive　amount　of　OMt,　the　pore　walls　of　the　nanocomposites　become　thick　and　their　average　pore　sizes　decrease.　When　the　additive　amount　of　OMt　varies　from　0　to　1.5 wt%,　the　mechanical　properties,　bulk　density　and　oxidation　resistance　of　the　nanocomposites　are　improved　and　their　thermal　conductivity　is　markedly　decreased.　For　the　nanocomposite　prepared　with　1.5 wt%　of　OMt,　its　bulk　density,　thermal　conductivity,　compressive　strength　and　modulus　arrive　at　0.35 g/cm3,　0.108 W/m·K,　6.90 MPa　and　207 MPa,　respectively.　©　2017　Elsevier　B.V.