In　an　energy　dissipation　structure,　the　seismic　mitigation　effect　of　dampers　is　depended　on　their　parameters　and　placements.　An　optimized　model　based　on　artificial　fish　swarm　algorithm,　was　proposed　for　the　optimal　design　of　displacement-based　dampers.　The　model　can　be　applied　in　structural　finite　element　models　with　multi　dimensions　and　degrees　of　freedom　to　determinate　the　placements　and　parameters　of　displacement-based　dampers　in　each　story.　In　order　to　deal　with　the　increment　of　story　shear　force　after　installing　displacement-based　dampers,　an　optimized　objective　function　was　proposed,　in　which　the　variation　of　maximum　story-drift　angle,　story　acceleration　and　story　shear　force　was　considered,　and　the　form　of　root　mean　square　(rms)　was　adopted　to　reflect　the　vibration　properties　of　each　story＇s　responses　in　the　process　of　earthquake　wave　excitation　more　effectively.　In　the　optimal　design　process　of　the　energy　dissipation　structure,　the　weighting　coefficients　of　the　objective　function　can　be　flexibly　adjusted　according　to　the　design　demands.　Some　examples　were　illustrated　to　verify　the　effectiveness　of　the　new　mathematic　model.　©　2016,　Chinese　Vibration　Engineering　Society.　All　right　reserved.