The present invention provides a method for producing a myocardial sheet using a group of cells derived from embryonic stem cells. This method is characterized by mixing Flk/KDR positive cells, cardiomyocytes, endothelial cells, and mural cells, all derived from embryonic stem cells, and culturing the mixed cells. Furthermore, the myocardial sheet can be used as a therapeutic agent for heart diseases since VEGF is released from the sheet.