The incidence of fungal infectious diseases has increased remarkably in vulnerable populations, such as immunnocompromised and cancer patients. However, as most of pathogenic fungi are opportunistic and belong to kingdom of eukaryotes, it is thought to be difficult to develop new antifungal drugs. Also, some fungi grow very slowly then we feel hard to detect these microorganisms quickly. So, as the basic researches to invent the prompt method for diagnosis and to discover new drugs for fungal infectious diseases, we have been studying about the functional characterization of several pathogenic yeasts. In this time, I would like to talk about two research topics of our advanced researches.