In 37 cases of locally advanced breast cancer, arterial administration of adriamycin (ADR), given a total dose of 150 mg in a single dose of 30 mg or 50 mg, was attempted as means of preoperative chemotherapy, and its tumor contraction action in the primary breast cancer and side effects were studied. On the basis of the "Assessement Criteria of Therapeutic Effects on Advanced and Recurrent Breast Cancer" by the Japan Breast Cancer Society, complete response (CR) was noted in 3 cases, and partial response (PR) in 25 cases, with an efficacy rate (CR+PR) of 75.7% (28/37 cases). There was no significant difference in the efficacy rate between the two groups and histological effects were statistically similar. Besides, regarding the difference in the route of administration, the clinical effects were more significant in the group administered from two routes of subclavian artery and internal thoracic artery than in the group injected only from the the subclavian artery. As for side effects, alopecia, leukocytopenia, anorexia, nausea and vomiting were found at high frequencies, and local toxicity was also recognized at a considerable rate, but there was no difference between single dose groups, and these adverse effects were considered to be permissible as far as the total dose up to 150 mg.