Aim To evaluate the impact of gene transfection of hypoxia inducible factor 1α to acute myocardial infarction of rat. Methods 72 healthy male Wistar rats weighting 250~350 g were divided into three groups:hypoxia inducible factor 1α gene transfection group (HIF-1α group),control goup and sham-operation group. Each group was divided into 3 d,7 d and 14 d subgroups; There are 8 rats in each subgroup. After the ligation of LCA,the total 50 μg plasmid HIF-1α and null plasmid were injected into the infarct zone at three locations in HIF-1α group and control group respectively. The sham-operation group did not undergo litigation of left anterior descending coronary. The mRNA expression of HIF-1α and capillary density were detected. The myocardial infarction size was measured. Results Capillary density increased significantly in HIF-1α group compared with the control group (P<0.01). The mRNA expression of HIF-1α increased significantly in HIF-1α group compared with the control group (P<0.01),while the myocardial infarction size decreased significantly (23.85%±2.25% vs 38.74±3.12%; P<0.01). Conclusion The gene transfection of hypoxia inducible factor 1α in myocardium of rat can reduce infarction size and enhance angiogenesis in acute myocardial infarction of rat.