A　new　method　is　proposed　for　the　motion　planning　problem　of　the　humanoid　robot　upper　body.　First,　the　kinesiology　model　is　built　based　on　the　physical　structure　characteristics　of　human　body　with　the　knowledge　of　mechanism　and　robotics.　Second,　considering　different　movement　characteristics　between　the　waist　and　the　arm,　two　human　performance　measures　are　comed　up:　joint　displacement　and　discomfort-potential　energy　that　are　then　combined　into　a　human　upper　body　motion　performance　index.　Third,　based　on　the　index,　a　new　motion　planning　algorithm　of　humanoid　robot　upper　body　is　proposed　utilizing　the　gradient　projection　method.　Finally,　the　feasibility　and　the　rationality　of　the　algorithm　are　verified　through　comparasion　between　the　Matlab　numerical　simulation　and　experiment　of　human　upper　body.　©,　2015,　Beijing　University　of　Technology.　All　right　reserved.