This　paper　studies　the　cooperative　mechanism　for　a　three-echelon　supply　chain　with　remanufacturing　outsourcing　comparing　a　supplier,　a　manufacturer,　and　a　third-party　remanufacturer,　wherein　we　take　the　relative　fairness　concerns　into　consideration.　The　Stackelberg　game　theory　is　introduced　to　analyze　the　best　values　for　the　supply　chain　and　each　member.　Nash　bargaining　solution　is　used　as　the　relative　fairness-concerned　reference　to　discuss　the　corresponding　optimal　solutions　of　these　models.　By　determining　and　comparing　the　equilibrium　solutions　across　the　five　models,　we　discover　that　given　the　Nash　bargaining　fairness-concerned　behavior,　the　system　profits　in　the　completely　decentralized　and　three　cooperative　scenarios　are　lower　than　they　are　for　products　in　the　completely　centralized　decision　model.　The　results　show　that　in　the　centralized　channel,　the　optimal　profit　and　market　demand　in　the　three-echelon　supply　chain　are　maximized.　Furthermore,　it　turns　out　that　a　cooperative　mechanism　can　bring　great　benefits　to　its　performance.　©　2021　Antai　College　of　Economics　and　Management,　Shanghai　Jiao　Tong　University.