A novel series of substituted benzoylguanidine derivatives were designed and synthesized as potent NHE1 inhibitors. Most compounds can significantly inhibit NHE1-mediated platelet swelling in a concentration-dependent manner, among which compound 5f (IC(50)=3.60 nM) and 5l (IC(50)=4.48 nM) are 18 and 14 times respectively more potent than cariporide (IC(50)=65.0 nM). Furthermore, when tested in vivo and in vitro, compound 5f showed superior cardioprotective effects against SD rat myocardial ischemic-reperfusion injury over cariporide, representing a promising lead compound for further exploration.