Abstract: Objective To investigate the correlation between helicobacter pylori (HP) infection and serum oxidized low-density lipoprotein (ox-LDL) level,severity of coronary artery disease in patients with coronary heart disease.Methods A total of 66 patients with coronary heart disease were selected,in which 33 patients without HP infection were designed as control group and 33 patients with HP infection were designed as observation group.The serum levels of ox-LDL and serum lipids were compared between the two groups.The relationship between HP infection and serum ox-LDL level was analyzed.The relationship between the level of serum ox-LDL and the severity of coronary artery lesions in patients with HP infection was analyzed.Results The levels of serum ox-LDL,TC,TG and LDL-C in the observation group were significantly higher than those in the control group (P ＜ 0.05).The serum ox-LDL level of the observation group was significantly higher than that of the control group,and the serum ox-LDL level of patients with severe infection in the observation group was significantly higher than that of patients with mild infection (P ＜ 0.05).There was a significant positive correlation between serum ox-LDL level and severity of coronary artery lesions in patients with HP infection (P ＜0.05).Conclusion HP infection in patients with coronary heart disease can lead to lipid metabolism disorders,elevate serum ox-LDL level,and increase the severity of coronary artery disease.