In　this　paper,　we　present　an　internal　model　based　output　feedback　control　for　the　cooperative　semi-global　output　regulation　of　nonlinear　strict-feedback　multi-agent　systems　with　arbitrary　non-identical　relative　degrees.　The　problem　is　first　converted　into　a　cooperative　semi　global　stabilization　problem　by　introducing　a　distributed　internal　model.　We　then　propose　a　distributed　output　feedback　stabilizer　that　is　determined　by　a　distributed　high-gain　observer.　It　is　shown　that　this　novel　observer　is　capable　of　estimating　the　states　of　nonlinear　subsystems　with　arbitrary　non-identical　relative　degrees.　(C)　2017,　IFAC　(International　Federation　of　Automatic　Control)　Hosting　by　Elsevier　Ltd.　All　rights　reserved.