A series of 6-(N-aylamono)-7-chloro-5, 8-quinolinedione derivatives was newly synthesized for the evaluation of antifugal activities. 5-Amino-8-hydroxy-quinoline (II) was treated with $KCLO_3$ in HCl to give 6,7-dichloro-5,8-quinolinediones (III). 6-(N-Arylamino)-7-chloro5,8-quinolinediones 1-13 were prepared by regioselective nucleophilic substitution of III with arylamines. In the presence of $CeCl_3$, the N-arylamono groups were introduced at the 6-position of 5,8-quinolinedione ring by the regioselective substitution. These derivatives 1-12 were tested for natifungal and also antibacterial activites, in vitro, against Canadida albicans, Aspergillus nier, Tricophyton mentagrophytes, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coil. The MIC values were determined by the two-fold agar/steak dilution method. Newly obtained 6-(N-arylamino)-7-chloro5,8-quinolinedione derivatives showed potent antifungal and antibacterial activities. Among these derivatives, 1,3,5,7,8 and 9 showed more potent antifungal activities than fluconazole and griseofulvin. Also most of derivatives were found to be more active than ampicillin against gram-positive bacteria. 1 and 7 showed the very potent antifungal activities. 1 was the most efective in preventing the growth of Candida albicans, Aspergillus niger, Tricophyton mentagrophytes, Bacillus subtills and Staphylococcus aureus at MIC $1.6\;\mu{g/ml}$.