Aim To evaluate the effects of Helicobacter pylori(Hp) eradication on coronary events and the serum levels of inflammation substances in acute coronary syndrome patiens.Methods 46 Unstable angina patiens and 110 acute myocardial infarction patiens with evidence of Hp infection were randomized into control group(n=82) and treatment group(n=74).Treatment group were treated with Omeprazole,clarithromycin and amoxicillin for ten days in addition to conventional therapy(control group) were used for Hp eradication.Results The follow up period was one year.The incidence of the coronary artery events were 6.76% in treatment group and 14.63% in control group,with a reduction of relative risk by 48.85% for treatment group(P=0.0246),Among them,incidence of non-fatal myocardial infarction reduced by 65.87% in treatment group compared to control group(5.41 %vs15.85%,P=0.0387);the incidence of the other events also decreased by 61.92% in treatment group compared to control group(14.86% vs 39.02%,P=0.005),Among them,the demand for PCI/CABG was 4.05% in treatment group and 14.63% in control group,with a reduction of relative risk by 72.35% in treatment group(P= 0.0252),readmission with angina reduced by 60.88% in treatment group compared to control group(8.11% vs 20.73%,P=0.0269).The serum levels of IgG,high sentsitivity C-reactive protein(hsCRP),soluble intercellular adhesion molecule-1(sICAM-1) and interleukin-6(IL-6) in treatment group were distinctly lower than those in control group after treatment(p<0.01 or p<0.05).Conclusion Hp eradication can significantly decrease the incidence of nonfatal myocardial infarction and readmission with angina and the demand for PCI/CABG.