Abstract: OBJECTIVE To evaluate the intracellular distribution and anti-cardiomyocyte apoptosis effect of baicalin PEG-PCL nanomicelle. METHODS Baicalin PEG-PCL nanomicelle were prepared by membrane hydration method. Coumarin-6 was used as a fluorescent probe to evaluate the uptake and intracellular distribution of PEG-PCL nanomicelle. Modeling of H9c2 cardiomyocyte apoptosis induced by 10 μmol·L^-1 isoproterenol was performed. The isodose baicalin and baicalin PEG-PCL nanomicelle were pretreated for 1 h before modeling, and the apoptosis-related caspase 3 activity, ROS levels and expression levels of Bcl-2 and Bax proteins were determined. RESULTS Baicalin PEG-PCL nanomicelle had excellent characteristics such as small particle size and slow release rate. Fluorescence tests showed that PEG-PCL nanomicelle can promote the cell uptake of drugs, and can also accumulate drugs in the mitochondria. The results of death test showed that baicalin PEG-PCL nanomicelle can significantly reduce apoptosis-related caspase 3 activity, ROS levels, reduce the expression of pro-apoptotic Bax, and significantly increase the expression of anti-apoptotic Bcl-2. There was a significant difference compared with the baicalin. CONCLUSION Baicalin PEG-PCL nanomicelle can promote the uptake of baicalin by cardiomyocytes and help to accumulate drugs in the mitochondria, thus greatly improving the anti-cardiomyocyte apoptosis effect.