A new morpholino anthracycline derivative, MX2, has a potent antitumor activity similar to adriamycin. Because of high lipid solubility of MX2 (log P = 2.84, pH 7.4), the compound can cross the blood-brain barrier easier than adriamycin. In this study we tested the anti-tumor activity of MX2 against human glioma in vitro and in vivo. MX2 showed a marked cytocidal effect against U105MG, U251MG, U373MG and KMG4 cells when more than 30 ng/ml was added in the medium. Although the sensitivity against MX2 differed depending on the cell lines, the cytocidal effect of MX2 was similar to adriamycin. The colony formation of KMG4 cells was markedly inhibited by MX2 dose-dependently. The growth of KMG4 cells inoculated subcutaneously into nude mice was inhibited by the intraperitoneal administration of MX2 4 or 1.3 mg/kg. These results suggest that MX2 seemed to be useful in the treatment of malignant glioma.