Abstract: AIM: To discover new potent quinolone antibacterial agents. METHODS AND RESULTS: A series of novel analogues of levofloxacin has been prepared. These compounds were evaluated for in vitro activity by determining minimum inhibitory concentrations against a variety of bacteria. The structure-activity relationships were also discussed. CONCLUSION: The results showed that the 8-amino group was very favorable for antibacterial activity. Compounds 13 and 14 were superior to the reference compounds levofloxacin and ciprofloxacin and were selected as promising candidates for further studies.