The invention discloses a preparation for treating leukemia. The preparation is prepared from, by weight, 8-13 parts of lophantherum gracile, 6-12 parts of polystichum deltodon, 7-11 parts of radix ophiopogonis, 9-13 parts of emilia sonchifolia, 8-14 parts of embelia parviflora, 6-11 parts of radix stellariae, 4-10 parts of laggera alata, 7-12 parts of radix ranunculi ternati, 6-13 parts of Callicar bodinieri Levl., 5-8 parts of colla corii asini, 7-13 parts of Excoecaria acerifclia F. Didr., 8-12 parts of dichrocephala auriculata, 6-10 parts of Bulbophyllum Inconspicuum Maxim and 5-12 parts of polygonum multiflorum. The preparation has the advantages that the preparation is capable of effectively preventing related complications caused by the leukemia, evidently adjusting body immune function, strengthening body resistance and dispelling evil, dispelling toxic materials, detoxifying and delaying or preventing relapse.