Abstract: By adding graphene oxide(GO) or graphite(G) in blending system of nitrile rubber(NBR) and polyurethane(PU), the GO/NBR-PU and G/NBR-PU ternary composites were prepared by the technology of hot-press moulding. The dynamic mechanic property of the GO/NBR-PU and G/NBR-PU composites were studied by DMA, FTIR, SEM and so on. The results suggest that the tangent of loss angle(tanδ), the storage modulus(E') and the loss modulus(E") of the GO/NBR-PU composites all present a trend of increasing originally and decreasing subsequently with the increase of GO content. At the same time, when the mass ratio of GO to NBR reach its critical value 3%, the composites have superior dynamic mechanic performances. As the graphite is added, the damping property and mechanical properties of the composites are enhanced, but the mechanical properties of the composites decrease with the increasing of more graphite content. Through microscopic analysis, the enhancement function of GO is mainly due to the interfacial effect. The main reason for the decrease of mechanical properties is the agglomeration of GO or graphite in NBR-PU composites.