Effects　of　the　radius　and　fire　heat　release　rate　on　the　smoke　propagation　and　smoke　control　in　curved　tunnel　are　studied　by　the　numerical　methods.　Six　radiuses　as　70　m,　150　m,　200　m,　250　m,　300　m　and　400　m　and　two　different　fire　sizes　as　5　MW　and　30　MW　are　involved.　Numerical　results　show　that　comparing　with　the　smoke　flow　in　the　straight　tunnel,　smoke　temperature　distributions　across　the　cross-section　is　not　symmetry　with　the　centerline　in　the　curved　tunnel,　and　the　smoke　diffusion　close　to　the　outside　boundary　appears　to　be　fast.　At　the　higher　level　of　the　curved　tunnel,　such　as　3　m　above　the　tunnel　floor,　the　smoke　temperature　would　decrease　with　the　distance　from　the　fire　increasing.　However,　at　the　lower　level　of　the　tunnel,　the　temperature　would　increase　firstly　and　then　decrease,　maximum　temperature　would　occur　in　the　bend　region　of　the　curved　tunnel.　When　the　fire　heat　release　rate　is　big,　this　temperature　might　be　high　enough　to　injure　the　people.　Smoke　ventilation　system　would　run　in　time　under　this　condition.　Critical　velocity　in　curved　tunnel　is　larger　than　that　in　the　straight　tunnel.　©　Published　under　licence　by　IOP　Publishing　Ltd.