The morphological, cultural, physiological and biochemical characteristics of a new actinomycete strain producing a new antibiotic, setamycin are described. The strain forms aerial mycelia. There is no fragmentation of vegetative mycelia. Since the cell wall type is a new one containing both LL- and meso-2,6-diaminopimelic acid, glycine and galactose, strain KM-6054 could not be classified in any previously named genera of the order Actinomycetales. Thus, it is considered to be a member of a new genus, for which the name Kitasatosporia is proposed. The type species (monotype) of this genus is K. setalba. The type strain of K. setalba is strain KM-6054 (ATCC 33774).