ThePurposeofthispaperisastudy on thecharacteristicsofCampidogliohillplan byMichelangelo. 1.TheplanoftheCampidogliohilliscomposedoftheharmonizedandunitedspace, in spiteoftheexisting conditionsofa steep flightofland,a irregularsiteshape,a building ofeach otherdifferentdimension and form.Anditisnewly changedby site left through the modification of existing building elevation,utilization of existing buildingfornew planning,connectionwithexistingbuildingandnewlyplannedbuilding from plazacompositionoftrapezoidform. 2.Theconceptofplanning oftheCampidogliohillisplanned by compromising for requirements of Baroque after Renaissance which urban planning characteristics of Baroqueisastherelationwithurbanstreetthroughainclinedstairsandprocesssuch asstreet-approachstairs-plaza-symbolofinsideplaza-building. 3.The section plan ofthe Campidoglio hillis planned by which can be easily approached to theplazathrough theinclined stairsofgentleanglefrom streetatthe centereast-westdirection ofmain axis such asmain axis,utilizing theexisting site shape,anditiscomposed oftheconvex shapeascending gently atthecentercentral partoftheplaza. 4.The plan ofthe Campidoglio hillis composed ofthe elation with the axis of existing Senatorio palace,building planning ofperfectbalance,plaza composition of reversedtrapezoidform bybuildingplanning,centralconcentratedplanningofbuildings surroundingplaza. 5.ThethreepalaceoftheplanoftheCampidogliohilliscomposedoftheconceptas theaterwhichthestagebackgroundformsthefrontelevationofSenatoriopalacehigher two palace and the wings of either side of stage form the front elevation of Conservatoripalaceand Nuovopalace,surrounding threepalaceelevation around plaza oftrapezoidform.