For　use　of　fire　prevention　and　suppression,　fire　simulations　are　in　demand　for　virtual　reality　effects,　helping　researchers　study　the　dynamics　of　fire　and　smoke.　In　this　paper,　by　extension　of　particle　system　hierarchies,　we　establish　a　multi-level　particle　system　model　(MLPSM)　which　not　only　could　be　top-down　controlled　to　enhance　the　dynamic　simulation,　but　can　be　managed　in　high　efficiency　to　increase　rendering　speed.　Applying　this　new　model,　we　further　formulate　a　simplified　model　of　fire　spread　and　present　a　visual　system　for　animating　fire　and　smoke,　using　OpenGL,　based　on　application　requirements.　The　results　show　a　well　balance　between　rendering　effects　and　real-time　display　with　10,000　particles,　which　proves　the　effectiveness　of　our　multi-level　particle　system　model.