With　more　and　more　natural　gas　has　been　transported　by　pipelines,　the　possibility　of　natural　gas　jet　fire　caused　by　inner　or　outer　factors　is　increased　gradually.　That　will　result　in　casualties　and　domino　effect　to　make　further　disaster　and　serious　loss　of　property.　It　is　imperative　to　study　jet　fire　and　prevent　jet　fire　happening.　This　paper　investigates　the　temperature　profile　for　square　and　rectangular　fuel　nozzle　(long　side　sets　along　transverse)　horizontal　jet　fires.　The　numerical　simulation　code　was　carried　out　to　simulate　jet　fires　with　different　jet　velocity　varied　from　27.5　m/s　to　205.8　m/s.　The　fuel　leak　area　for　square　and　rectangular　was　same　(400　mm2),　but　the　aspect　ratio　(width　/　length,　W/L)　were　1:1　and　1:4,　respectively.　Results　show　that　the　temperature　increase　with　the　jet　velocity,　and　the　relationship　between　maximum　temperature　along　centreline　and　jet　velocity　is　closed　to　line　which　slope　is　1.82.　The　simple　function　for　this　connection　was　established.　The　maximum　temperature　of　vertical　direction　locates　at　1m　from　centreline,　and　the　maximum　temperature　increase　with　jet　velocity.　The　temperature　along　centreline　for　rectangular　flame　is　less　than　square　flame　at　same　point　and　the　high　temperature　area　along　horizontal　direction　is　less.　It　is　deduced　the　rectangular　nozzle　results　in　flame　shorter　and　more　width　due　to　larger　relative　surface　area　and　air　entrainment.　The　high　temperature　area　in　transverse　direction　for　rectangular　nozzle　is　greater　than　square.　©　2017　The　Authors.　Published　by　Elsevier　Ltd.