A　high-efficiency　smoke　exhaust　system　is　very　important　for　the　occupants＇　safe　escape　from　a　large-space　building　in　fire.　The　smoke　exhaust　rates　are　determined　by　the　theory　of　the　two-layer　model　and　some　empirical　plume　equations.　Whether　these　systems　can　maintain　a　tenable　environment　for　the　evacuation　is　a　question,　especially　in　the　building　with　irregular　inner　shape.　The　performance　of　the　smoke　exhaust　system　in　two　atria　with　irregular　shape　is　studied　by　fire　models　in　this　paper.　A　two-layer　zone　model　and　a　computational　fluid　dynamics　field　model　developed　by　the　Building　and　Fire　Research　Laboratory,　National　Institute　of　Standards　and　Technology,　USA,　are　used.　Numerical　results　are　compared　with　experiments　through　hot　smoke　test　in　the　two　atria.　Both　the　fire　models　can　predict　well　and　are　suitable　for　evaluating　the　performance　of　the　smoke　exhaust　system.