Objective：To analyze the characteristics of multislice spiral computed tomography (CT) for acute myocardial infarction.Methods: The anterior descending coronary arteries of 6 pigs were ligated at the 1/3 distal end to establish acute myocardial infarction model without reperfusion.Dual multislice spiral CT scanning was performed in all animals and the CT characteristics were analyzed.Results: Acute myocardial infarction model was successfully established in all 6 animals.Myocardial perfusion deficits were detected during early phase scanning; the area of deficits were significantly decreased during late phase scanning (13.52%±5.22% vs 9.07%±3.47%,P=0.004),with a mean decrease of 32.14%.CT value of different myocardial varied at different scanning times: the values of LV cavity decreased from (586±111) HU to (294±53) HU (P=0.001),that of the normal myocardial area decreased from (247±54) HU to (132±25) HU (P=0.001); the values of the perfusion deficit regions were not significantly changed (\[42±14\] HU vs \[29±23\] HU,P=0.289).During late phase scanning,CT value around residual perfusion deficit was higher than that of normal myocardium (\[156±21\] HU vs \[132±25\] HU,P=0.004).Conclusion: The dual-phase MSCT characteristics of AMI include early perfusion deficits,late enhancement and residual perfusion deficits.Early phase scanning may overestimate the infarction area.