Objective To observe the effect and safety of helicobacter pylori eradication by doxycycline, levofloxacin,bismuth potassium citrate combined with omeprazole.Methods 240 patients who infected helicobacter pylori were selected,and were randomly divided into four groups:treatment group(doxycycline,levofloxacin,bismuth potassium citrate,omeprazole),control group A(doxycycline,levofloxacin,omeprazole),control group B(amoxicillin, clarithromycin,bismuth potassium citrate,omeprazole),control group C (amoxicillin,clarithromycin,omeprazole), 60 patients in each group.Helicobacter pylori eradication treatment for 7 days,patients with gastritis stop after the course of the treatment,peptic ulcer patients continue taking omeprazole 5 weeks after 7 days treatment.All patients stopped medicine 2 weeks accepted 14 carbon breath test.And adverse events were investigated.Results In the treatment group and the control group A,B,C,the helicobacter pylori eradication rates were 93.3%,80.0%,91.7%, 75.0%.Compared with group A,the treatment group helicobacter pylori eradication rate increased significantly(χ2 =4.61,P <0.05 ).Compared with group C,the treatment group helicobacter pylori eradication rate increased significantly(χ2 =7.57,P <0.05).But compared with group B,the treatment group helicobacter pylori eradication rate had no significant difference(χ2 =0.12,P >0.05).Compared with the treatment group,group B had high inci-dence of oral odor(χ2 =6.56,P <0.05).Compared with the treatment group,group C had high incidence of oral odor (χ2 =5.46,P <0.05).Conclusion Doxycycline,levofloxacin,bismuth potassium citrate combined with omeprazole can improve the helicobacter pylori eradication rate significantly,and with low price,has little side effect,no need of penicillin skin test,can used for the patients poverty or allergic to penicillin.