A hypoxic stress which causes apoptosis of cardiomyocytes is the main problem in the ischemic heart disease. The present research sought to investigate the role of microRNA-29b1 (miR-29b1) in hypoxia-treated cardiomyocytes and its potential mechanism involved. We replicated an in vitro AC16 and H9C2 cardiomyocytes ischemia model by hypoxia (1% O₂, 48 h) treatment. Cell apoptosis was evaluated by flow cytometry using Annexin V FITC-PI staining assay. Moreover, we used western blot and immunofluorescence analysis to determine the expression of Bcl-2, Bax caspase-3 and Cx43 proteins. We found that miR-29b1 protected AC16 and H9C2 cells from hypoxia-induced injury as the evidences that miR-29b1 attenuated the effects of hypoxia treatment on AC16 and H9C2 cell apoptosis after hypoxia treatment. In conclusion, these results revealed the potential cardiovascular protective effects of miR-29b1 in the process of ischemia-related myocardial injury.