6-[(N-3,4-Dibromophenyl)amino]-7-chloro-5,8-quinolinedione(RCK13) was tested for antifungal activities. The MIC values were determined by the two-fold dilution method. The therapeutic potential of RCK13 had been assessed in comparison with ketoconazole and fluconazole against systemic infections with Candida albicans in normal mice. RCK13 had ED_(50), 0.80±0.21 mg/kg but ketoconazole had ED_(50), 8.00±0.73 mg/kg respectively. And administered RCK13 at the ED_(50) for 14 days improved survival rates as well as ketoconazole. Acute oral toaicity studies of RCK13 were carried out in ICR mice of both sexes. These acute oral toxicities of RCK13 were low and LD_(50) values were over 2,850 mg/kg in ICR mice. The genotoxicities of RCK 13 had been evaluated. RCK13 was negative in Ames test with Salmonella ryphimurium and chromosomal aberration test in CHL cells. The clastogenicity was tested on the RCK13 with in vivo mouse micronucleus assay. RCK13 did not show any clastogenic effect in mouse peripheral blood and was negative in mouse micronucleus assay. These results indicate that RCK13 has no genotoxic potential under these experimental conditions.