Abstract: OMMT/EVA-g-PU nanocomposites were prepared through the method of melting graft and melting intercalation. The characterization of FTIR and ¹³C-NMR indicates that —NCO terminated polyether-polyurethane prepolymer is grafted on the EVAL main chain successfully. The dispersion state of OMMT in matrix was observed by XRD and TEM. The mechanical properties and storage modulus and thermal stability were studied by the microcomputer-cont rolled electronic tensile tester and DMA and TG. The results indicate that the chief dispersion state of OMMT in EVA-g-PU matrix is intercalated. When the mass fraction of OMMT is 3%，the tensile strength，Young‘s modulus and tear strength are 7.96 MPa，7.12 MPa and 49.97 MPa，respectively. The storage modulus of nanocomposites increase with the increase of OMMT amount . When the mass fraction of OMMT is 7%，the storage modulus of nanocomposites is 2 times than that of pure EVA. The thermal stability of OMMT/EVA-g-PU nanocomposites is far superior to that of pure EVA with the increase of OMMT amount .