PROBLEM TO BE SOLVED: To provide a blood purification apparatus and retransfusion method thereof, which excellently perform retransfusion even when power supply is stopped by power interruption, etc.SOLUTION: The blood purification apparatus includes: a blood circuit 1 including an arterial side blood circuit 1a with a blood pump 2 arranged therein and a venous side blood circuit 1b a dialyzer 4 for purifying the blood of a patient, which is extracorporeally circulated in the blood circuit 1 a dialysate introduction line L1 for introducing a dialysate to the dialyzer 4 a dialysate discharging line L2 for discharging the dialysate from the dialyzer 4 and filters (7a, 7b) connected to the dialysate introduction line L1 to filter and purify the dialysate flowing in the dialysate introduction line L1. The apparatus also includes a control means 10 for driving the blood pump 2 while supplying the dialysate in the filters (7a, 7b) to the blood circuit 1 when performing the retransfusion to return the blood in the blood circuit 1 to the body of the patient.
