To　manage　a　large-scale　complex　structure　effectively　and　reduce　damage　lost　induced　by　disasters　and　structural　material　deterioration,　it　is　nowadays　a　focus　to　investigate　and　develop　a　large　structural　health　monitoring　(SHM)　system.　Sensor　arrangement　takes　an　important　role　in　the　SHM　system　due　to　its　characteristics　not　only　depending　on　the　system　performance　but　also　impacting　on　the　management　cost.　In　this　paper,　the　sensor　arrangement　methods　used　commonly　were　introduced　firstly,　and　then　a　novel　sensor　arrangement　method　based　on　structural　vulnerability　analysis　was　proposed.　In　which,　the　important　factors　of　members　are　calculated　first,　and　the　redundancy　of　each　members　is　obtained　by　the　relation　of　the　redundancy　and　important　factor;　then　the　failure　modes　are　searched　and　determined　by　the　redundancy;　afterwards　the　strain　energy　of　a　structure　is　presented　to　evaluate　the　damage　demand　of　a　failure　mode;　consequently　the　fragility　failure　path　is　determined;　furthermore,　the　sensors　are　arranged　based　on　the　fragility　failure　path.　A　truss　bridge　model　was　validated　the　proposed　method　finally.　The　results　show　that　the　proposed　method　is　feasible　and　effective.