Abstract: The tribological property of UHMWPE and its composites reinforced by Graphene Oxide (GO) were investigated using the UMT-3MT reciprocating friction testing apparatus under the lubrication medium of sodium hyaluronate (SHA). The surface topographies and the wear rate of these composites were observed and evaluated by a high-resolution scanning electron microscope and an Micro-XAM three-dimensional surface profiler. The results demonstrate that the wear rate of GO/UHMWPE composites was reduced significantly as the increasing content of GO under the lubrication medium of SHA, but no significant differences were found in the steady coefficient of friction and the characteristic of the wear debris in SHA was the same as that produced by the pure UHMWPE. The wear resistance of UHMWPE was improved markedly with the addition of GO filler.