Mountainous　tunnel　portal　section　is　one　of　the　most　easily　damaged　parts　during　strong　earthquake.　Failures　of　this　part　may　block　roads,　which　greatly　influences　the　transportation　of　the　local　area　after　earthquake.　Model　tests　on　shaking　table　of　tunnel　portal　section　are　carried　out.　A　rigid　testing　box　is　adopted　in　the　tests.　The　rock　condition　around　tunnel　portal　section　is　designed　rather　weak　as　the　rock　in　this　part　is　often　weathered　and　loose.　A　new　similarity　material　with　a　main　component　of　fly　ash　has　been　successfully　made　to　simulate　the　surrounding　rock.　Test　with　a　model　scale　of　1:50　are　designed.　Slope　angles　are　set　to　35°　according　to　the　slope　range　limited　by　the　rock　type.　By　the　testing　results,　the　rule　of　tunnel　portal　failure　under　the　condition　is　studied.　The　results　can　be　references　for　other　similar　projects　and　for　seismic　damping　measure　design.　©　2013　Taylor　&　Francis　Group.