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 .