Due　to　the　complex　coupling　motion　of　shoulder　mechanism,　only　a　small　amount　of　quantitative　information　is　available　in　the　existing　literature,　although　various　kinematic　models　of　the　shoulder　complex　have　been　proposed.　This　study　focused　on　the　specific　motion　coupling　relationship　between　glenohumeral　(GH)　joint　center　displacement　variable　quantity　relative　to　the　thorax　coordinate　system　and　humeral　elevation　angle　to　describe　the　shoulder　complex.　The　mechanism　model　of　shoulder　complex　was　proposed　with　an　algorithm　designed.　Subsequently,　twelve　healthy　subjects　performed　right　arm　raising,　lowering,　as　well　as　raising　and　lowering　(RAL)　movements　in　sixteen　elevation　planes,　and　the　motion　information　of　the　markers　attached　to　the　thorax,　scapula,　and　humerus　was　captured　by　using　Vicon　motion　capturing　system.　Then,　experimental　data　was　processed　and　the　generalized　GH　joint　with　floating　center　was　quantized.　Simultaneously,　different　coupling　characteristics　were　detected　during　humerus　raising　as　well　as　lowering　movements.　The　motion　coupling　relationships　in　different　phases　were　acquired,　and　a　modified　kinematic　model　was　established,　with　the　description　of　overall　motion　characteristics　of　shoulder　complex　validated　by　comparing　the　results　with　a　prior　kinematic　model　from　literature,　showing　enough　accuracy　for　the　design　of　upper　limb　rehabilitation　robots.