The disclosure provides a method of freezing an aggregate of pluripotent stem cell-derived cardiomyocytes, comprising:(i) immersing an aggregate of pluripotent stem cell-derived cardiomyocytes in a cryoprotective solution； and(ii) freezing the aggregate immersed in the cryoprotective solution.The disclosure also provides a frozen aggregate of pluripotent stem cell-derived cardiomyocytes frozen by the method.
