Clinical application of recently developed anti-fungal drugs including fluconazole and itraconazole has provided great advantages in the treatment of deep mycoses. However, pathogenic fungi belong to eukaryotes including humans and are phylogenetically apart from prokaryotes, i.e. bacteria. In other words, the components and metabolic pathways of fungi and mammals are very similar. This sometimes makes it difficult to treat severe mycoses with the anti-fungal drugs available at present. Therefore, new drugs which are more selective for fungal components, such as new azoles, are desired by clinicians and some of them are now under clinical trial. Fungal factors involved in dimorphic change including transcription factors and members of MAP kinase cascades as well as virulence factors including proteases, phospholipases and catalase have recently been identified. These factors and enzymes responsible for cell wall construction could be selective targets to develop new anti-fungal drugs.