Objective: To investigate selected cardiovascular responses of post myocardial infarction patients(PMIP)during exercise within the context of different levels of ST segment depression. Method: Forty-six male recent PMIP performed a graded exercise test on a motorized treadmill during which time blood pressure and heart rate were measured and a 12 lead electrocardiogram (ECG) was monitored continuously. They were then subdivided into those ST segment depression ＜1.0 mm at exercise stage Ⅱ (group 1) and those who had ST segment depression ＞1.0 mm at this stage (group 2). Result: The results showed that the patients with a larger degree of ST segment depression at the given work load exhibited higher a value of rate-pressure product (RPP).Conclusion: RPP may be of particular value in estimating the clinical response to exercise when ECG monitoring is not available.