To　study　the　application　of　continuum　structural　topology　optimization　methods　to　real　engineering　structures,　an　optimization　method　for　an　optimal　topology　design　of　multistory　steel　frame　bracing　systems　is　presented.　On　a　sensitivity　analysis,　an　element　removal　criterion　for　continuum　structures　with　stress　and　multi-displacement　constraints　under　multiple　lateral　loading　conditions　is　proposed.　A　concept　of　mean　thickness　of　a　design　domain　is　provided　to　ensure　the　reasonableness　of　optimal　results.　In　the　proposed　optimization　method,　the　optimal　design　of　an　unbraced　steel　frame　without　displacement　constraints　is　performed　firstly,　and　then　the　optimal　topology　of　a　bracing　system　for　the　multistory　steel　frame　considering　displacement　constraints　is　obtained　by　using　evolutionary　structural　optimization　and　the　given　removal　criterion,　and　finally　the　optimal　layout　of　the　bracing　system　is　interpreted　as　bracing　members.　An　example　of　3-bay　12-story　plane　steel　frame　shows　that　it　is　effective　for　the　given　optimization　method　in　the　optimal　design　of　bracing　systems　for　multistory　steel　frames.