Objective:To study the changes of cell activity and viability of cardiac myocyte and cardiac non-myocyte which irradiated by high power microwave (HPM).Methods:cardiac myocyte and cardiac non-myocyte were irradiated by HPM. Then cell apoptosis and necrosis were detected by flow cytometer; and cell activity was examined by MTT experiment.Results:HPM can influence the function and morphology of the two kinds of cells obviously, and induce their apoptosis and necrosis.Conclusion:Heart maybe is one of the most susceptible organs to microwave. Meanwhile, the experiment suggest that we should attach importance to cardiac non-myomyte irradiated by HPM.