On studying of microbes and appearance frequency which are floating around dwelling space and life environments in Seoul area, the results are summarized as follows ; 1. 1931 strains of 29 bacteria are isolated in dwelling spaces, Among them, there are Staphylococcus aureus, S. anthracis which are pathogenic to human beings. 2. In fungi, 76 strains of 13 species are isolated. That of highest frequency is confirmed to be Aspergillus which is pathogens of Aspergillosis (one of a group of diseases of animals and human being caused by various species of Aspergillus). The places, where the number of kinds and the frequency of appearances have been observed highest, are coffee shops, lunch counters and office rooms, while factory districts are of far lower level than expected. 3. 0.1% $HgCl_2$, Leasking oil, and Telephone disinfectant were better than any other in fungicidal effect.