Sporaricin A, an aminoglycoside antibiotic containing a 1,4-diaminocyclitol was found by Deushi et al1) in the culture filtrate of Saccharopolyspora hirsuta subsp. kobensis. Related N-formimidoyl antibiotics, 2''-N-formimidoylfortimicin A (dactimicin)2) and 2'-N-formimidoylistamycins A and B3) were found by Inouye et al and by Kondo et al in culture filtrates of Dactylosporangium matsuzakiense SF-2052 and Streptomyces tenjimariensis SS-939, respectively. In this paper, we will report the isolation and characterization of another related antibiotic, 2"-N-formimidoylsporaricin A produced by the strain MG937-14F1. This strain was isolated from a soil sample collected at a garden of our Institute and classified into Saccharopolyspora hirsuta subsp. kobensis.4) The production of 2"-N-formimidoylsporaricin A by the sporaricin-producing strain has never been reported before.