This　paper　has　studied　numerically　and　experimentally　the　airflow　characteristic　in　ventilating　and　smoke　exhausting　in　subway　station　and　tunnel　fire.　From　the　present　numerical　simulation　results,　it　is　clarified　that　the　huge　calculation　flow　field　concerned　can　be　simplified　as　that:　when　the　fire　takes　place　in　a　subway　station,　the　computational　area　is　the　station　with　one　station　and　two　tunnels　on　each　side,　and　when　the　fire　takes　place　in　a　subway　tunnel,　the　computational　area　is　the　tunnel　with　two　stations　and　one　tunnel　on　each　side,　in　this　case,　all　the　inlets　and　outlets　can　be　set　as　free　boundary　conditions.　Simulating　results　are　mostly　the　same　as　experimental　results.