Abstract: Objective To investigate the correlation between gyrA gene mutation of isolated helicobacter pylori (HP) strains and Levofloxacin (LVX) resistance in Dongtai area of Yancheng city. Methods Forty?five gastric mucosal tissues from patients with peptic ulcer,who underwent gastroscopy in the Department of Gastroenterology,Dongtai Hospital Affiliated to Nantong University between May 2013 and October 2013,were included in the study. All gastric mucosal tissues were cultured on Columbia agar plate containing selective inhibitor for 3?5 days under microaerobic condition(5%O2,10%CO2,85%N2). Twenty?three Hp strains were isolated and cultured,and tested for their sensitivity to LVX using the E?test method. The LVX?resistant strains and sensitive strains were screened. The DNA of Hp strain genome was extracted,then the sequence analysis was performed after gyrA gene fragment was amplified by PCR. Results The rate of LVX resistantce was 47.8%(11/23). Among 11 LVX?resistant strains,10 had gyrA gene mutations chiefly including Asn?87(n=6),Asp?91(n=3),and Val?172(n=1). Conclusion The rate of LVX resistance in Hp is high in the Dongtai area,which is correlated with gyrA mutations chiefly presenting as Asn?87 and Asp?91 of amino acid mutations.