Streptomyces sp. TPR-885 which produced the new antibiotics, kujimycins, was isolated from a soil sample from the Kuji District of the Ibaragi Prefecture, Japan. The strain belonged to a chromogenic type of Streptomyces similar to St. spinichromogenes, St. griseochrontogenes and St. cavourensis. From the taxonomic studies, the strain TPR-885 resembled with St. spinichromogenes in the morphological and physiological properties. This strain was accordingly named Streptomyces spinichromogenes var. kujimyceticus. It produced in excess of 150 mcg/ml of kujimycins in flask and jar fermentation, and the kujimycins showed inhibitory activities against gram-positive bacteria and Mycobacteria.