In our rat model, we have found that: 1) the plasma levels of HMGB1, IL‐6, IL‐8, TNF‐α and IL‐12 were increased in the rat model of MI/RI; 2) the expression of HMGB1, TLR4 and NF‐κB protein and mRNA was up‐regulated in the myocardium; and 3) the migration, adhesion and aggregation to the myocardium CD1a+CD80+ cells increased significantly, which was consistent with the increase in the expression of ICAM‐1, E‐Selectin, and P‐Selectin. The gene discussed is HMGB1; the disease is myocardial infarction.