During the course of screening for new antitumor antibiotics, the cultured broth of microorganism strain 1029-AVI (isolated from a soil sample in Kaho, Fukuoka, Japan and identified as Actinomadura roseoviolacea) showed marked antitumor activity and was found to contain a new anthracycline antibiotic named akrobomycin. This communication reports the isolation, characterization, and biological activities of akrobomycin. The strain was cultured at 27°C for 7 days in a medium composed of 2.5% glucose, 1.5% soybean meal, 0.2% dry yeast, and 0.4% CaCO₃ (pH 7.4). The culture filtrate was purified via Diaion HP-20, silica gel, and Sephadex LH-20 column chromatography to obtain pure akrobomycin as a reddish purple powder (8 mg). Physicochemical properties of akrobomycin include: mp 143–148°C; UV/Vis (MeOH) λmax nm (E₁%₁cm) 255 (472), 268 (548), 490 (238), 513 (262), 550 (162); IR (KBr) 1593 cm⁻¹ (quinone and aromatic C=C); FAB-MS m/z 482 ([M+H]⁺); elemental analysis consistent with C₂₆H₂₇NO₈ (calcd: C 64.86, H 5.65, N 2.91; found: C 64.79, H 5.69, N 2.87). Structural analysis via ¹H NMR and acid hydrolysis (yielding daunosamine and decarbomethoxybisanhydro-rhodomycinone) revealed akrobomycin as 9,10-anhydro-13-deoxocarminomycin. Antimicrobial activity (agar dilution method) showed inhibition of Gram-positive bacteria (e.g., Staphylococcus aureus IFO 12732 MIC 6.25 μg/ml, Micrococcus luteus ATCC 9341 MIC 3.13 μg/ml) and Trichophyton mentagrophytes (MIC 25 μg/ml), but no activity against Gram-negative bacteria, yeasts, or fungi. Antitumor activity against P388 leukemia in CDF₁ mice (intraperitoneal injection on days 1 and 5) resulted in survival prolongation with T/C ratios of 128–153%. The intraperitoneal LD₅₀ in mice was >20 mg/kg. Further studies on biological activity are ongoing.