Abstract : Objective To analyze the expression and significance of serum long non-coding RNA ( LncRNA) H19 and micro RNA-625-5p ( miR-625-5p) in children with peptic uleer ( PU ) complicated by Helicobacter pylori ( HP ) infection. Methods A total of 160 children with PU who were treated in our hospital from February 2021 to February 2023 were selected, including 90 patients with HP infection ( positive group) and 70 patients without HP infection ( negative group)，and 160 healthy children in the same period as the control group. The relative expression levels of LncRNA H19 and miR-625-5p were detected by real-time fluorescence quantitative PCR ( qRT-PCR). The Pearson method was applied to analyze the corelation between the expression levels of LncRNA H19 and miR-625-5p in children with PU and HP infection. The association of LncRNA H1 9h and miR-625-5p with HP infection in children with PU was analyzed by the logistic regression, and the value of the expression of LncRNA H19 and miR-625-5p in the diagnosis of HP infection in children with PU was analyzed by the receiver operating characteristic ( ROC) curve analysis. Results Compared with the control group, the levels of serum LncRNA H19 in the HP negative group and positive group were obviously increased in turn ( P<0.05) ,and the levels of serum miR-625- 5p were obviously decreased in turn ( P<0.05). Compared with HP infection type I， the levels of serum LncRNA H19 in children with HP infection type II were obviously reduced ( P<0.05), and the levels of serum miR-625-5p were obviously increased ( P<0.05). There was a binding site between LncRNA H19 and miR-625-5p, and there was an obvious negative correlation between serum LncRNA H19 and miR-625-5p levels in children with PU complicated by HP infection (r=-0.536, P<0.05). Logistic regression analysis showed that LncRNA H19 was a risk factor for HP infection in children with PU (P<0.05), and that miR-625-5p was a protective factor affecting HP infection ( P<0.05). The areas under the ROC curve ( AUCROC) of serum Ln-cRNA H19 and miR-625 5p in diagnosing HP infection of children with PU were 0. 870 and 0.895, respectively, and the AUCROC of their combination was 0.935, which was better than their respective diagnosis alone (imin.LnxH= 1.991, P=0.023; A.mi.im-a-625_5 =1.707, P= 0.044). Conclusion The levels of serum LncRNA H19 in children with PU complicated by HP infection increase, while the levels of serum miR-625-5p decrease, which may have certain diagnostic value for PU complicated with HP infection.