<p>The present invention addresses the problem of providing a technique that makes it possible to store an organ or tissue for transplantation use for a long period while maintaining the function of the organ or tissue. The present invention also addresses the problem of providing a technique for preventing the warm ischemia/reperfusion-induced damage on a tissue in an organ from a donor in cardiac arrest and recovering the condition of the organ to a level appropriate for transplantation utilizing the above-mentioned technique. A method for maintaining a mammalian organ or tissue for transplantation use for a long period employing perfusion with a perfusate, said method comprising (a) a step of connecting a perfusate inflow cannula for allowing the inflow of the perfusate into the "organ or tissue", (b) a step of connecting a perfusate outflow cannula for allowing the outflow of the perfusate from the "organ or tissue", and (c) a step of perfusing the perfusate containing an oxygen transporter and a blood coagulation inhibitor into the organ or tissue; and others.</p>
