<;P>;PROBLEM TO BE SOLVED: To provide a transplantable myocardial cell sheet required for myocardial regenerative therapy related to cardiac transplantation therapy for mammals. <;P>;SOLUTION: The transplantable myocardial cell sheet for the mammals is obtained by culturing myocardial cells of the mammals in a culture dish having the surface coated with a temperature-responsive polymer. The resultant cell sheet improves a cardiac dilating and contracting ability and/or suppresses remodeling of the heart. <;P>;COPYRIGHT: (C)2004,JPO