Objective To investigate the feasibility of recovering the cardiac structure and improving the cardiac function after the transplantation of embryonic stem cellsD3 (ES-D3) combined with basic fibroblast growth factor (b-FGF) into the acute myocardial infarction (AMI). Methods Forty Wistar rats were used and randomly divided into 5 groups equally, including the normal control group (group 1), the myocardial infarction without treatment group (group 2), the medium injected group (group 3), the ES-D3 transplanted group (group 4),the combination of ES-D3 and bFGF transplanted group (group 5).One week after the acute myocardial infarction (AMI), rats were injected with the in vitro differentiated ES-D3 labeled by BrdU. Then the cardiac function and histology were measured in week 4 after the transplantation. Results ES-D3 could differentiate into cardiomyocytes in vitro, and could survive steadily for 4 weeks in vivo after the transplantation into AMI’s model. There were no significant difference between group 2 and group 3 in cardiac function（P>0.05）. Compared with group 2, the infarction size and left ventricular weight(LVW) were reduced significantly（P<0.01）in group 4 and group 5， and capillary density was increased significantly（P<0.01）. The functions of the left ventricle were remarkably improved. Conclusion The t