In　the　present　study,　considering　the　internal　heterogeneity　of　concrete,　a　meso-scopic　simulation　method　was　established　to　explore　the　dynamic　compressive　behavior　of　heterogeneous　concretes　at　and　after　elevated　temperature.　In　the　meso-scale　numerical　model,　the　concrete　was　regarded　as　a　tri-phase　composite　material　consisting　of　aggregate,　mortar　matrix　and　the　Interfacial　Transition　Zones　(ITZs).　Both　the　high-temperature　degradation　effect　and　the　strain　rate　enhancement　effect　of　the　mesa-components　were　taken　into　account.　The　simulation　method　involved　two　steps:　(1)　the　heat　conduction　behavior　was　simulated　initially;　and　(2)　using　the　＂result　output＂　as　＂initial　conditions＂,　the　dynamic　mechanical　behavior　of　concrete　was　simulated.　Based　on　the　great　agreement　between　numerical　simulation　results　and　the　experimental　observations,　the　dynamic　uniaxial　compression　failure　behavior　and　meso-scale　failure　mechanism　of　concrete　at　and　after　elevated　temperature　were　studied.　Furthermore,　the　effect　of　high　temperature　on　the　macroscopic　dynamic　compressive　strength　and　elasticity　modulus　of　concrete　were　revealed.　The　results　indicate　that　the　concrete　specimen　still　shows　significant　strain　rate　effect　at　and　after　elevated　temperature　while　the　mechanical　properties　of　concrete　specimens　after　natural　cooling　further　degenerates　comparing　with　those　at　elevated　temperature.　(C)　2018　Elsevier　Ltd.　All　rights　reserved.