Fungi present in indoor environment are one of contaminant sources that affect on indoor air quality. When they become air-borne particles, fungi could serve as pathogens and/or irritants that cause infection, allergy, asthma, and dermatitis and trigger itching and coughing. To get scientific information on fungal bioaerosol, we investigated fungal concentration and diversity in indoor air of diverse buildings in Korea. Culture-based measuring method of ISO 160000 was used for fungal sampling. The level of fungal concentration ranged from 100 to 1,000 cfu/m3. Among the investigated buildings, the highest level of fungal concentration was found in sauna bath facility buildings. In general, the level of fungal concentration was higher in underground buildings than above ground buildings. About 4,000 fungal isolates were obtained from indoor air samplings which were performed from 2006 to 2016. Morphological and molecular methods were used for species identification. 99 genera and 233 species were identified. Ascomycota (83.2%) was dominant group followed by basidiomycota (15.88%), zygomycota(0.02%), and oomycote(0.004%) groups. Among ascomycota, eurotiomycetes containing Penicillium and Aspergillus species was 40.2%, indicating it is dominant taxon group in indoor air of diverse buildings. Incase of basidiomycota, agaricomycetes containing Trametes species was dominant taxon (91.89%). Among the identified 233 species, Alternaria tenuissima was dominant species, followed by P. funiculosum, and Aspergillus niger. When dominant Penicillium and Aspergillus species were grown at different conditions, they produced good quality conidiospores only at certain growth conditions. However, they could produce spores at diverse ranges of pH and temperature. These data imply that they are present as bioaerosol in indoor air in diverse buildings.