Fungal spores in indoor air may come from outdoor by ventilation of they may originate within. when these spores set favourable conditions they proliferate on the book covers and cause the deterioration. The aerial survey of intramural fungal spores was carried in Agriculture college Library Nagpur for two years. The samples were collected at 15 days internals with portable hi air sampler, simultaneously exposure petriplate method applied. Total 2930 colonies were recorded from feb. 2004 to Jan 2006 by exposure petriplate method. Total 1380 and 1350 colonies were trapped in first and second year of investigation respectively. Qualitatively 22 genera were identified. Dominant genera were Aspergillus, Cladosperium, penicillium, Curvalaria, Alternaria Chactomium, Cunninghamela, By air Sampler method. Total 16290 CFUS/M3 were trapped in two years of study. In 2004-05 total 8455 CFUs.M3 and in 2005-06 total 7835 CFUS/M3 were recorded. Comparatively in rainy season maximum incidence of fungal spore was observed followed by winter and summer season.