Controlling interfacial microstructure and interactions between (ultra high molecular weight polyethylene) UHMWPE fiber and matrix is of crucial importance for the fabrication of advanced polymer composites. In this paper, (UHMWPE fiber-g-graphene oxide [GO]) was prepared. GO nanoparticles distributed onto the fiber surface uniformly, which could increase surface polarity and roughness. Increases of interlaminar shear strength (ILSS) and interfacial shear strength (IFSS) of UHMWPE fiber-g-GO composites were achieved. These enhancements can be attributed to the existent of GO interface with providing chemical bonding and strong mechanical interlocking between the fiber and matrix. Moreover, impact resistance of UHMWPE fiber-g-GO composites was enhanced. [GRAPHICS] SEM images of different UHMWPE fiber surfaces: (a) Untreated UHMWPE fiber, (b) UHMWPE fiber-APS, (c) UHMWPE fiber-ad-GO and (d) UHMWPE fiber-g-GO; (e) GO-ad.