Objective To establish a method to isolate, culture and purify cardiomyocytes with high survival rate, stronger dynamic frequency and high purity from neonatal rats. Methods The cardiomyocytes were digested with 0.08% trypsin and 0.05% typeⅡ collagenase, and then differentially attached for 60 min, and finally 5-Brdu(final concentration of 0.1 mmol·L~(-1)) was added to purify them. The morphological changes and beating rate of myocardial cells were recorded under an inverted version of microscope at differe...