Abstract：To investigate the impact of human activities on indoor air quality, real-time monitoring of PM_2.5and particle numbers was carried out at five typical indoor locations in the campus of Xi 'an Jiaotong University.The relevant information such as human activities and ventilation information was recorded simultaneously. The results show that the particle number concentrations and PM_2.5mass concentrations vary as different human activities. The average concentrations of particle number (242 266 cm^-3) and PM_2.5mass (124.2 μg/m³) in the student canteen are much higher than other indoor environment, showing that cooking activities is a major contributor to indoor particulate pollution. Mopping is a recommended cleaning method since it significantly reduces indoor particle loadings. People should shorten exposure hours and enhance ventilation when they are doing cooking activities.

Keywords：human activities; fine partiulate matter (PM_2.5) ; air quality