The pharmacokinetic properties of KRN 8602, an anthracycline compound, was studied by HPLC following intravenous administration of KRN 8602 to cancer patients. The results were as follows. (1) The plasma concentration-time curve declined as a triphasic function (alpha, beta, gamma) (t1/2 (alpha) = 0.02910, +/- 0.0054 hr, t1/2 (beta) = 0.704 +/- 0.319 hr, t1/2 (gamma) 8.37 +/- 1.37 hr). The blood cell concentration was higher than that in plasma. (2) The distribution volumes of the tissue compartment were larger than those of the central compartment. This result suggested that KRN 8602 would be easily transferred into the tissues. (3) The area under the curve (AUC) of KRN 8602 increased in proportion to the increase of dosage. (4) The metabolites of KRN 8602 were detected in plasma, blood cell and urine. (5) Urinary excretion of KRN 8602 and its metabolites were extremely low.