Aim To explore relationship between Helicobacter pylori （Hp） infection and serum oxidized low density lipoprotein （ox-LDL） in carotid artery atherosclerosis patients. Methods 129 cases with carotid atherosclerosis diagnosed by carotid artery ultrasonography in our hospital were chosen, ¹⁴C urea breath test was used to detect Hp infection situation of the selected object. Meanwhile enzyme-linked immunosorbent method is used to determine the serum levels of ox-LDL. Results Serum ox-LDL, total cholesterol （TC）, low density lipoprotein cholesterol （LDLC） and triglyceride （TG） levels of patients with carotid atherosclerosis in Hp infection group were higher than that of Hp non-infection group, and the differences were statistically significant （P<0.05, P<0.01）. With carotid atherosclerosis in patients with Hp infection in vivo degree aggravating, its serum ox-LDL level also increased accordingly. The differences of serum ox-LDL level in different degree of Hp infection groups were statistically significan （F＝13.169, P<0.01）, and pairwise comparisons among the three groups, serum ox-LDL level differences were statistically significant （P<0.05）. Multiple linear regression analysis showed that serum levels of ox-LDL was significantly increased in Hp infected patients. Conclusion Helicobacter pylori infection may cause lipid metabolic disorders in a certain extent, increase serum levels of ox-LDL, and promote the development of the carotid atherosclerosis.