In order to reduce toxic effects while attaining maximal therapeutic effects, epirubicin 10 mg/day, cyclophosphamide 100 mg/day and prednisolone 10 mg/day were administered through in indwelling catheter inserted into the internal mammary artery and/or subclavian artery for 3-4 weeks, employing the implantable port system for the treatment of unresectable breast cancer and recurrent cancer. Ten out of 11 patients (91%) with unresectable breast cancer showed a response (CR 3, PR 7, NC 1) to this modality of intra-arterial infusion chemotherapy. Seven out of 11 patients (64%) with recurrent cancer of the breast showed a response (CR 1, PR 6, NC 4). Intraarterial infusion chemotherapy for the unresectable advanced breast cancer and recurrent breast cancer proved to be an effective modality of treatment.