The object of the present invention is to provide a joint prosthesis, bearing material and a production method thereof, which suppresses wear in a sliding section and suppresses the production of abrasive powder even during repeated daily operation. To achieve the object, there is provided a biomaterial comprising: a substrate made of metal, alloy or ceramic and a biocompatible material layer laminated on the substrate, wherein hydroxyl groups are formed on the substrate by surface-treating, while the biocompatible material layer comprises a polymer containing phosphorylcholine groups, the substrate and the biocompatible material layer are bound via a binder layer which is combined with the hydroxyl groups of the substrate and with the biocompatible material layer.
