AIM:To elucidate the influences of H pylori infection on oral iron treatment for iron deficiency anemia(IDA). METHODS:A total of 86 patients were divided into two groups:group A,receiving ferrous succinate combined with triple therapy for H pylori eradication,and group B(control),treated with ferrous succinate only.During treatment of IDA,dynamic changes in hemoglobin(Hb) level,mean corpuscular volume(MCV),mean corpuscular hemoglobin(MCH),serum iron(SI),and serum ferritin (SF)were compared between the groups. RESULTS:Hb was slightly higher in group A at d 14 after the start of triple therapy for H pylori eradication (P>0.05).After the therapy,the increase of Hb in group A became significantly faster than that in group B (P<0.05).At d 56,the mean Hb in group A returned to the normal level,however,in group B,it was lower than that in group A(P<0.05)although it had also increased compared with that before oral iron treatment.The MCV and MCH in group A recovered to the normal level,and were much higher than those in group B(P<0.05)at d 21.In Group B,the MCV and MCH remained at lower than normal levels until d 42 after the start of therapy. And then,they reached a plateau in both groups and the differences disappeared(P>0.05).The SF in group A was higher than that in group B(P<0.05)28 d after the treatment and its improvement was quicker in group A (P<0.05),and the difference between the two groups was even more significant(P<0.01)at d 56.The SI in group A was higher than that in group B(P<0.05)at d 14 and this persisted until d 56 when the follow-up of this research was finished. CONCLUSION:Treatment of H pylori can enhance the efficacy of ferrous succinate therapy in IDA patients with H pylori-positive chronic gastritis.