An organ anastomosis marker is provided with a plurality of marker portions, a connecting member and a string-like member. The marker portions are formed with an elastic member that reflects ultrasound waves. The marker portions are circular in the no-load state. The connecting member connects the plurality of marker portions at a preset interval. The string-like member has one end fixed to one of the plurality of marker portions which is located on the end. The other end of the string-like member has a length that leads outside the body.