Fire　safety　in　tunnels　is　a　concern　due　to　the　large　traffic　flow,　especially　in　a　tunnel　with　a　great　slope.　Experimental　studies　on　the　smoke　spread　in　a　small-scale　titled　tunnel　are　carried　out.　Effects　of　the　titled　gradients　and　longitudinal　ventilation　speed　on　the　temperature　distribution　and　smoke　stratification　downstream　from　the　fire　along　the　tunnel　will　be　studied.　The　results　show　that　the　smoke　spread　upwards　much　faster　with　the　slop　gradient　increasing,　and　a　thick　smoke　layer　was　formed　when　smoke　moved　to　the　upward　part　of　the　tunnel　and　filled　it　up.　The　ventilation　speed　had　a　great　influence　on　temperature　distribution　along　the　tunnel.　Lower　ventilation　speed　should　be　kept　at　the　start　of　the　fire　to　ensure　the　smoke　layer　not　be　destroyed　downstream　of　the　fire　to　give　the　tunnel　users　more　time　to　escape.　©　2016　Taylor　&　Francis　Group,　London.