Offshore　wind　power　foundations　are　known　to　bear　complex　loadings,　not　only　vertical　loading　V　induced　by　self-weight,　but　also　horizontal　loadings　H　induced　by　wind,　wave　and　current,　and　the　bending　loading　M　transferred　from　superstructure.　In　this　paper　a　framework　for　evaluating　the　bearing　capacity　of　the　foundations　is　presened　and　the　bearing　characteristics　of　offshore　wind　power　foundation　under　combined　horizontal,　vertical　and　bending　loadings　are　analyzed.　The　bearing　capacity　of　offshore　wind　power　foundation　under　unidirectional　horizontal,　vertical　and　bending　loadings　is　examined,　and　the　relationship　between　the　ultimate　bearing　capacity　and　the　ratio　of　diameter　to　length　of　pile　foundation　is　obtained.　Based　on　the　side-swipe　method,　the　envelope　of　bearing　capacity　and　failure　mode　of　offshore　wind　power　foundation　in　V-H,　V-M,　H-M　loading　space　and　V-H-M　loading　space　are　studied　in　details,　and　the　parameter　analysis　of　the　envelope　of　foundation　bearing　capacity　in　different　loading　space　are　discussed.　Finally,　a　simple　and　practical　method　is　proposed　to　judge　the　stability　of　the　offshore　wind　power　and　the　seabed.　A　verification　example　reveals　that　the　estimates　of　the　presented　framework　shows　good　agreement　with　observations.