The novel epoxidized soybean oil-modified-phenolic resin/clay nanocomposites(ESO-M-PR/CN)was prepared.The coupling agent-benzyldimethylphenylammonium chloride [C6H5CH2N+(CH3)2C6H5Cl-,B2MP]was adopted to modify the interface between the organic and inorganic phases.The effect of the nanocomposite structure on its physical and chemical properties was discussed.During the synthesizing process of ESO-M-PR/CN,the phenol hydroxyl was etherified by ESO or ESO epoxy resin prepolymer to provide long ESO epoxy segments.Long ESO epoxy resin chain segments enhanced the crosslink density of ESO-M-PR/CN.The thermal and mechanical properties exhibit a significant improvement.The temperature at which a weight loss of 5%Occurs increases from 287.1℃to 402.3℃.The flexural strength increases by 25%,while the flexural modulus increases by 39%.Moreover,the properties of resin were enhanced by the effect of the inorganic nanoparticles,while the size of the nanomontmorillonites in the phenolic resin was characterized with a scanning electron microscope.The particle size of inorganic montmorillonites in the modified system is less than 100 nm.