The　Huangtupo　riverside　slope,　which　extends　an　area　of　1.35　x　10(6)　m(2)　and　has　a　total　volume　of　6.934　x　10(7)　m(3),　is　one　of　the　most　noted　large-scale　landslides　with　great　concern　about　the　safety　of　immigrants　in　the　Three　Gorges　reservoir　area　of　China.　During　the　normal　operation,　the　reservoir　water　level　fluctuates　periodically.　Water　level　fluctuation　will　soften　the　strength　of　the　geologic　materials　on　the　banks,　induce　underground　water　fluctuation,　and　in　turn　affect　the　slope　stability.　On　the　basis　of　the　thorough　engineering　geological　survey,　the　analysis　of　engineering　geological　conditions　and　deformation　mechanism　is　conducted　primarily.　Then,　the　Huangtupo　landslide　is　divided　into　four　minor　landslides,　all　of　which　have　typical　three-dimensional　characteristics.　To　these　landslides,　a　three-dimensional　rigorous　limit　equilibrium　method　is　proposed,　which　can　accommodate　failure　surfaces　of　any　shape,　and　satisfies　all　the　equilibrium　conditions.　In　terms　of　the　strength　parameters　of　geologic　materials,　the　stability　evolution　of　the　four　minor　landslides　at　the　Huangtupo　landslide　under　periodical　water　level　fluctuation　is　investigated　in　detail.　From　the　results,　the　3D　safety　factors　turned　out　to　be　somewhat　bigger　than　the　2D　results　even　though　they　displayed　the　same　trends.　The　differences　between　2D　and　3D　results　are　about　2.92-6.11　%.　The　maximum　reduction　in　safety　factors　with　the　rapid　down　of　water　level　is　0.11.　It　is　suggested　that　the　safety　margin　of　the　two　minor　landslides　near　the　riverside　is　insufficient　and　might　become　instable　under　periodical　water　level　fluctuation.