In　order　to　study　the　influence　of　steel-concrete　composite　slab　on　the　seismic　behavior　of　steel　frame　structure,　the　beam-stratified　shell　mixed　models　of　profiled　steel　sheeting-concrete　composite　slabs　are　set　up　with　the　spatial　composite　effect　on　slabs　taken　into　consideration.Pushover　analysis　and　dynamic　incremental　analysis　are　made,　respectively,　of　a　steel　frame　structure　with　and　without　slabs,　and　the　influence　of　composite　slabs　on　the　seismic　behavior　of　steel　frame　structure　in　elasto-plastic　working　state　under　earthquake　is　presented.　It　can　be　found　that　the　slab　spatial　composite　effect　will　enhance　the　strength　of　beams　so　as　to　increase　structural　lateral　stiffness　and　bearing　capacity　and　decrease　structural　period　and　displacement　response.But　the　slab　spatial　composite　effect　may　reduce　structural　ductility,　hysteresis　quality　and　energy　dissipation,　and　even　change　the　structural　expected　failure　mode　of＇strong　column　and　weak　beam＇,　which　is　likely　to　make　the　structure　unsafe.　©　2018,　Editorial　Board　of　Journal　of　Tianjin　University(Science　and　Technology).　All　right　reserved.