A field study was carried out in a campus to present the quantitative results of indoor bio-aerosols. Four sites with distinct purpose of use were conducted in this study. The objective was to characterize microbial air quality in the campus of this university located in Taipei. The aerosol concentration of bacteria and fungi were collected and measured by methods of NIEA E301.10C and NIEA E401.10C for air quality management. Four stations, such as the classroom, elevator, meeting room, and toilet with the different activities in the school, were compared and analyzed with the spatial and temporal distribution of bio-aerosols. The bio-aerosol concentration is depended on the ventilation factor for different sites. The results reveal the violation of indoor air quality standards in some sites. It is suggested to conduct a control program to improve the indoor air quality and protect the health of students in the place of worse indoor air quality.