Here,　a　real　project　of　a　three-tower　self-anchored　suspension　bridge　(TSSB)　was　taken　as　a　background.　Spatially　varying　non-stationary　ground　motions　were　simulated　according　to　real　site　condition.　Based　on　the　finite　element　model　of　TSSB,　the　time　history　method　was　used　to　discuss　effects　of　ground　motion　spatial　variations,　such　as,　wave　passage　effect,　coherency　loss　effect　and　local　site　effect.　On　seismic　response　of　TSSB,　respectively.　Results　showed　that　spatially　non-uniform　ground　motions　increase　seismic　response　of　towers　and　decreases　safety　factor　against　cable　sliding;　it　is　necessary　to　consider　effects　of　ground　motion　spatial　variations　in　seismic　design　of　TSSB.　Further　studies　showed　that　the　levels　of　the　impacts　of　spatially　ground　motion　on　each　component　are　different　and　influence　rules　of　different　spatial　effects　are　also　quite　different;　the　influence　laws　of　spatially　ground　motion　on　seismic　response　of　TSSB　are　very　complicated,　more　in-depth　study　on　this　topic　is　needed.　©,　2015,　Chinese　Vibration　Engineering　Society.　All　right　reserved.