We extracted Astragalosides (AS) from Astragalus membranaceus, a nature herb using as a Chinese traditional medicine, and postulated Astragalosides would exert beneficial effect in myocardial injury by preserving both energy metabolism and Ca2+ homeostasis. Sprague-Dauley (SD) rats were injected with isoproterenol (ISO) s.c. at a dose of 5mg/kg/day consecutively for two days. Astragalosides and trimetazidine were treated to isoproterenol-administrated rats by injecting i.p. at a dose of 5mg/kg/day one day prior to isoproterenol and lasted for 8 days, respectively. The histological changes were alleviated in isoproterenol-damaged SD rats treated with astragalosides. Compared with those in isoproterenol group, myocardial intracellular [Ca2+]i was decreased, L-type Ca2+ density and sarcoplasmic reticulum (SR) Ca2+ load were improved by astragalosides administration. Meanwhile myocardial ATP content was increased, phosphocreatine (PCr) was decreased in the same group. In conclusion, astragalosides is expected to be an efficacious treatment for myocardial injury by regulating intracellular Ca2+ homeostasis and energy metabolism.