An organ preservation system includes an organ container, an organ holder, a liquid supply tube, a drainage tube, and a pressure regulator. The organ container has a closed organ preservation space. The organ holder holds an organ in the organ preservation space. The liquid supply tube supplies a liquid to the organ. The drainage tube drains the liquid from the organ. The pressure regulator regulates air pressure in the organ preservation space. The organ container includes first to third connectors providing communication between the organ preservation space and an exterior space. The first, second, and third connectors are detachably connected to a liquid supply tube, a drainage tube, and a suction tube, respectively. When the organ is preserved ex vivo while being perfused with the liquid, the organ can be connected with ease to the tubes, and this ensures hermetical sealing of the space where the organ is preserved.