An object of the present invention is to establish a cell transplantation method which can markedly improve the survival of grafted pluripotent stem cells and the efficiency of cardiomyocyte regeneration in cell therapy using pluripotent stem cells derived from heart tissue and can treat heart disease further effectively. Specifically, according to the present invention, enhancement in the survival of grafted pluripotent stem cells and significant improvement in the efficiency of cardiomyocyte regeneration are achieved by using, in combination, pluripotent stem cells derived from heart tissue and a hydrogel containing a basic fibroblast growth factor (bFGF) in cell therapy for heart disease.