Reinforced　concrete　structures　may　suffer　some　accidental　loadings,　such　as　fire,　impact(or　blast),　etc.To　study　the　effects　of　high　temperature　and　impact　on　the　performance　of　RC　slabs,a　three-dimensional　simulation　model　was　established　in　the　present　work.　A　two-step　analysis　methodwas　utilized　to　consider　the　combined　effect　of　fire　and　impact　loadings.　Namely,　the　thermal　conduction　behavior　of　the　concrete　slab　was　simulated　firstly,　and　then,　the　＇result　output＇ofthe　temperature　field　was　used　as　the　＇initial　condition＇　to　simulate　the　impact　behavior　of　RC　slabs.　On　the　basis　of　verifying　the　rationality　of　the　three-dimensional　simulation　model,　the　influence　of　fire　exposure　time　on　the　impact　performance　of　RC　slabs　was　analyzed.　The　difference　of　impactperformances　between　RC　slabs　under　high-temperature　exposure　and　after　cooling　downwas　discussed.　Thus,　the　failure　mode　and　failure　mechanism　of　the　RC　slabswere　revealed.　The　simulation　results　showed　that　the　impact　performance　of　RC　slabs　subjected　to　fire　and　cooling　down,　in　terms　of　failure　pattern,　overall　deformation,　energy　dissipation,　responses　of　impact　and　reaction　force　as　well　as　acceleration,　is　better　than　that　under　high-temperature　exposure,　but　still　worse　than　that　at　room　temperature.This　difference　becomes　larger　with　respect　to　fire　duration.　As　the　fire　duration　increases,　the　residual　bearing　capacity　and　natural　frequency　which　reflects　the　overall　stiffness　of　the　RC　slab　decrease,　but　the　displacement　and　energy　dissipation　increase.　©　2020