Current　architecture　specifications　for　structural　design　is　based　on　reliability　calculation　of　structural　members,　which　considers　little　systematic　characters　of　structure　and　cannot　reflect　integrated　structural　reliability.　Therefore,　a　method　of　resistance　adjustment　for　structural　system　was　put　forward　in　this　article,　which　consisted　of　two　steps,　i.e.　reliability　analysis　of　structural　system　and　reliability　adjustment　to　structural　system.　The　main　reference　for　resistance　adjustment　to　structural　system　is　that　according　to　ratio　of　reliability　index　for　every　failure　mode　to　responding　target　reliability　index,　we　can　distribute　and　adjust　reliabilities　for　every　failure　mode.　So　that　reliability　index　of　structural　system　could　be　used　as　parameters　in　architecture　structural　design,　which　is　a　simple　and　practical　way　of　structural　reliability　design.　It　is　concluded　through　the　reliability　analysis　of　structural　system　of　a　double　layer　and　twin　spans　frame　that　it　needs　a　few　major　failure　modes　to　work　out　the　failure　probability　of　frame　structure　system　with　limited　calculation　error,　which　can　meet　the　requirement　for　engineering　design.