Methotrexate-γ-aspartate is a Ll210 cell dihydrofolate reductase inhibitor. Methotrexate-γ-aspartate is apparently more resistant to enzymic cleavage than is methotrexate-y-glutamate. Methotrexate-γ-aspartate can be used in antibody-targeted liposomes and is promising for research of leukemic.