The quartz crystal microbalance (QCM)was used to monitor the dynamic adhesions of neonatal rat primary cardiomyocytes and the subsequent viscoelastic changes induced by different concentrations of inotropic drugs onto the gold crystal electrodes in a non-invasive and real-time manner. The adhesion of neonatal rat primary cardiomyocytes onto gold electrode surface, and the subsequent drug effects of different concentrations of cardiomyocyte positive inotropic drug isoprenaline and cardiomyocyte negative inotropic drug verapamil, were monitored through the frequency (F)and motional resistance (R)measurements of the QCM in a real-time way. Cell viscoelastic index CVI (CVI=ΔR/ΔF)was used to characterize the viscoelastic changes of the cells, and the drug-induced morphological changes of the cells were observed by optical microscope. The results showed that with the increase of isoprenaline concentration, the magnitudes of QCM frequency drop, R increase and CVI increase all increased; whereas with the increase of verapamil concentration, the magnitudes of QCM frequency increase, drops in both R and CVI all increased. Cells’ contraction under the treatment of isoprenaline was observed under optical microscope, which is consistent with the result of increased CVI indicating that the cells became stiffer; while cells’ relaxation under the treatment of verapamil was observed under optical microscope, which is consistent with the result of decreased CVI indicating that the cells became softer. Our results suggest that the QCM has a great application potential as a tool in cardiovascular drug screening and evaluations.