In　China,　there　are　1.848　million　postgraduate　students　at　school　by　2014.　They　spend　more　than　half　of　the　time　doing　scientific　research　in　research　student　offices.　In　order　to　understand　indoor　air　quality　(IAQ)　in　these　offices,　indoor　climate　and　carbon　dioxide　(CO2)　concentration　were　investigated　in　a　typical　naturally　ventilated　postgraduate　student　study　room　in　a　university　of　China　during　heating　season.　Results　demonstrated　that,　due　to　high　occupancy　rates,　indoor　CO2　level　often　exceeded　1000　ppm,　even　reaching　a　peak　value　of　3000　ppm.　During　occupied　time,　average　of　77.6%　of　measured　CO2　data　each　day　exceeded　the　threshold.　The　longest　duration　of　exposure　to　CO2　concentration　more　than　1000　ppm　had　an　average　of　3.68　h　per　person　per　day.　These　results　implied　that　the　research　student　office　required　attention　in　meeting　acceptable　IAQ.　(c)　2017　The　Authors.　Published　by　Elsevier　Ltd.