Based　on　a　self-　Anchored　suspension　bridge　with　it　three　towers　a　3D　finited-element　model　is　developed　to　establish　its　defomied　equilibrum　configuratbn　due　to　dead　loadiig　Starting　from　defomed　configuration　a　modal　analyst　is　perfomied　to　provirle　the　frecpiencies　and　mode　shapes　Strutrural　and　material　paranetric　studbs　shav　hat　tensbn　stiffness　of　cable　vertical　bending　stillness　of　stringer　selfweght　of　deck　and　riser　span　ratio　play　an　important　role　in　the　dynamic　characteristics　of　self　anchored　suspension　bridge　it　three　towers.