Graphene　oxide/bismaleimide(BMI)　resin　nanocomposites　were　prepared　by　solvent　exfoliation　and　dispersion　method.　The　nanocompoistes　were　characterized　by　XRD,　TEM　and　TGA.　In　addition,　mechanical　properties　of　the　nanocomposites　were　studied　in　this　paper.　The　results　show　that　graphenen　oxide　can　be　obtained　by　ultrasonic　exfoliation　of　phenyl　isocyanate-modified　graphite　oxide　in　N,　N-dimethylformamide　solution.　The　nanocomposites　exhibit　better　mechanical　properties　than　the　neat　BMI　resin.　When　the　content　of　graphene　oxide　is　1%　of　BMI　resin,　the　nanocompoistes　have　the　best　mechanical　properties,　as　indicated　by　that　the　tensile　strength,　flexural　strength　and　impact　strength　of　the　nanocomposites　arrive　at　87.7　MPa,　142.1　MPa　and　15.9　kJ/m2,　respectively.　In　addition,　the　thermal　stability　of　the　nanocomposites　is　improved　with　graphene　oxide　content　increasing.　When　the　content　of　graphene　oxide　is　1.25%　of　BMI　resin,　the　carbonization　yield　of　the　nanocomposites　reaches　41.3%　at　1000°C.