Abstract: According to Langendorff's method, 4'-methylrecordil and recordil were infused into the isolated rabbit heart. It was shown that these drugs increased coronary artery blood flow, but did no change the myocardial contractibility and heart rate. A study of the uptake of ⁸⁶Rb by the mouse heart showed a marked increase of nutritional blood flow in the 4'-methylrecordil-treated group and persantine-treated group, but no such effect was observed in the recordil-treated and control groups.In order to determine the effect of the drugs on experimental myocardial infarction, we have Produced the model of myocardial infarction by high level doublerligation of the anterior descending branch of the left coronary artery in rabbits. The size of infarcted myocardium and the therapeutic effect of drugs were estimated by using the summation of ST segment elevation (ΣST), the total numbers of ECG lead with elevated ST segment (NST) and pathologic Q wave (NQ), and myocardium N-BT staining method. After ligation of the coronary artery, all animals were given introvenously the drugs immediately, then once every 12 hours, for a total of six doses. The animals were sacrificed three days after operation. It was demonstrated that in the 4'-methylrecordil-treated group, the ΣST, NST and NQ were significantly less than those in the control group. The size of infarct myocardium was also reduced significantly. Similar results were found in the recordil and persantine-treated groups. However, no obvious difference was present among the treated groups.