A method of an incomplete ischemia of the lateral wall of the left ventricle produced by pulling the ventricular branch of the left coronary artery of rabbits was employed in this study and the dispersion of the effective refractoriness used as an index. It was noted that the effective refractory periods at the different sites in AMI region were mainly shortened and the dispersion of refractoriness increased obviously. Nevertheless, EA at Neiguan acupoint could inhibit reduction of the effective refractory of ischemic myocardium and improve the dispersion of refractoriness markedly, which would be beneficial to synchronization of the myocardial excitatory state. It suggests that EA have some effect of anti-arrhythmia.