Under　the　conditions　of　large　population　in　China,　the　original　level　of　service　couldn＇t　meet　the　needs　of　subway　station　managers.　From　the　interdisciplinary　perspective　of　physiology,　medical　science,　and　engineering,　this　study　conducted　a　series　field　experiment　to　investigate　the　influence　of　passenger　flow　density　on　the　pedestrian　physiology.　By　quantitatively　analyzing　density　and　fluctuating　rate　of　heart　rates,　a　significant　finding　is　that　pedestrians＇　physiological　characteristics　are　influenced　by　the　traffic　density　in　corridor,　and　the　FRHR　is　high　associated　with　density,　presenting　a　linear　correlation.　In　the　end　of　paper,　the　LOS　is　divided　into　six　levels,　caring　on　the　refined　classification　for　higher　density,　in　line　with　China＇s　national　conditions.　Research　results　could　provide　a　theoretical　foundation　and　application　reference　for　subway　transit　designer　and　manager.