This　study　selected　a　petroleum　refinery　located　in　Northern　China　to　calculate　its　VOCs　emission　amount,　by　combing　its　ambient　atmospheric　VOCs　concentration　monitored　in　March　and　ISCST-3air　quality　model.　The　monitoring　results　showed　the　average　TVOCs　concentration　in　receptors　and　in　background　were　28.6×10-9　and　88.3×10-9　respectively.　In　addition,　there　were　significant　differences　between　receptors　and　background　in　the　VOCs　chemical　composition.　Ethane,　propane　and　ethylene　were　the　dominant　component　in　background,　but　the　volume　percentage　of　propylene,　isobutane,　butane,　isopentane,　pentane　increased　significantly　in　receptor.　It　was　indicated　the　VOCs　emitted　from　petroleum　refinery　had　a　large　impact　on　local　environment.　The　chemical　profile　of　refinery　VOCs　emissions　was　obtained　by　subtracting　VOCs　in　background　from　those　in　receptors,　and　the　main　compounds　included　ethane　(23.4%),　propane　(11.8%),　butane　(10.4%),　isobutene　(9.0%),　pentane　(5.3%),　isopentane　(6.4%),　propylene　(11.5%),　which　was　similar　to　the　literature　results　in　China.　The　inversion　results　of　ISCST-3model　showed　the　annual　VOCs　emission　was　2201.6±1011.9t/a,　with　the　VOCs　emission　factor　of　0.73g　VOCs/kg　crude　oil.　This　result　was　smaller　compared　to　the　researches,　possibly　due　to　two　reasons:　1,　lower　ambient　temperature　in　spring　resulted　in　the　less　evaporation　emissions;　2,　the　local　chemical　decay　of　VOCs　was　not　included　in　ISCST-3model.　©,　2015,　Chinese　Society　for　Environmental　Sciences.　All　right　reserved.