Panaxatriol (PT) is a natural product derived from ginseng that possesses cardioprotective effects in isolated rat hearts. To develop more potent therapeutic agents against myocardial ischemia/reperfusion (MI/R) injury from natural products, a novel series of heterocycle ring-fused panaxatriol derivatives were designed and synthesized. In vitro results showed that approximately half of them exhibited increased cytoprotective activity compared with PT in a cardiomyocyte model of oxygen-glucose deprivation and reperfusion (OGD/R) injury. Furthermore, the in vitro activity of the representative derivative, compound 18, was also confirmed in a rat model of MI/R injury. In vivo results showed that 18 can markedly reduce myocardial infarction size, decrease circulating cardiac troponin I (cTnI) leakage, and alleviate cardiac tissue damage in the rats. Therefore, these findings provide the basis for further development of novel anti-MI/R injury agents.