Aiming　at　the　theoretical　modelling　and　characteristic　analysis　of　ball　bearing　under　the　ball-raceway　separation　condition,　the　new　initial　position　for　ball　bearing　modelling　is　proposed.　Combining　with　the　ball-raceway　contact　analysis,　a　general　model　for　ball　bearing　under　different　load　conditions　is　presented.　Then　the　proposed　model　is　solved　by　a　nested　Newton-Raphson　iterative　algorithm　based　on　the　analytical　calculation　method　for　bearing　stiffness　matrix.　On　this　basis,　the　load　distribution　and　stiffness　characteristic　of　ball　bearing　under　three　different　load　conditions　are　analyzed.　The　results　show　that　the　proposed　model　is　more　reasonable　and　applicable　than　the　Jones-Harris　model.　Moreover,　the　internal　load　distribution　and　stiffness　are　determined　by　both　the　external　load　and　internal　contact　state　of　ball　bearing,　and　the　number　of　balls　in　loaded　zone　caused　by　the　changes　of　the　radial　clearance,　external　load　and　speeds　can　further　lead　to　the　sudden　change　of　bearing　stiffness.　In　addition,　appropriate　increases　of　axial　load　can　effectively　improve　the　load　distribution　and　increase　the　numbers　of　balls　in　loaded　zones　of　ball　bearing.　©　2020　Journal　of　Mechanical　Engineering.