Abstract: A blood collecting apparatus for collecting and reserving blood lost from the patient during or after operation, wherein thrombus contained in the collected blood is removed, and it is possible to prevent the new generation of the thrombus. The apparatus may readily be used safely. The apparatus includes a blood collecting container, a suction pipe having a branched pipe provided with a sterilizing filter, a collecting pipe provided with a port for supplying a blood anti-coagulant and a blood filter, and a discharge pipe having a blood filter. These pipes are connected to an upper part of the container. A suction unit is connected to an end portion of the suction pipe. A catheter or the like is connected to the end of the collecting pipe. The section unit is operated to suck and collect the blood from the incision during or after the operation.