In this work, a compatibilizer (UHMWPE-g-GO) with large specific surface was prepared from graphene oxide (GO) and ultra-high molecular weight polyethylene (UHMWPE). First, GO was modified by 2, 3-epoxypropyltrimethylammonium chloride (GTA), subsequently grafted with UHMWPE. UHMWPE-g-GO was used to compatibilize the immiscible monomer casting (MC) nylon/UHMWPE blends. With the addition of very low content of UHMWPE-g-GO, the compatibility of UHMWPE and the matrix (MC nylon) was remarkably improved without visible agglomerates, which was proved by photographs, scanning electron microscope, dynamic thermomechanical analysis, and contact angle measurement. Therefore, thermal stability, mechanical and tribological properties were obviously increased. A dramatic increment of 94.1% in the impact strength and a decrement of 39.4% in the coefficient friction were observed in the presence of UHMWPE-g-GO in the immiscible polymer blends. The approach used in this work was an efficient strategy for immiscible polymer blends with ultra-high molecular weight. (C) 2016 Society of Plastics Engineers