To investigate the protective effects of Shexiang Tongxin Dropping Pill (, STP) on Na2S2O4-induced hypoxia-reoxygenation injury in cardiomyoblast H9c2 cells. The cell viability and levels of mRNA and protein expression in H9c2 cells were determined following Na2S2O4-induced hypoxia using Hoechst staining, annexin V/propidium iodide (PI) flow cytometry, real-time polymerase chain reaction and Western blot analysis. STP pretreatment significantly increased the viability and inhibited aberrant morphological changes in H9c2 cardiomyoblast cells induced by Na2S2O4 treatment (P<0.05). In addition, STP pretreatment attenuated Na2S2O4-induced hypoxic damage, down-regulated the expression of pro-apoptotic Bax, and up-regulated the expression of anti-apoptotic Bcl-2 in H9c2 cells (P<0.05). STP was strongly cardioprotective in hypoxia-reoxygenation injury by preventing hypoxic damage and inhibiting cellular apoptosis. These results further support the use of STP as an effective drug for the treatment of ischemic heart disease.