The invention relates to an application of a hydroxyl benzopyrone compound for preparing a medicament for treating leukemia, belonging to the field of chemical medicaments. A compound of formula (I) shown by an experiment), especially compound icaritin of formula II can restrain CML (Chronic Myeloid Leukemia) cell proliferation in a mode of concentration dependent and induce apoptosis of marrow cells of a CML patient in the mode of concentration dependent, can obviously reduce the number of leukocyte of peripheral blood and CD45+ leukemia cell proportion, can obviously lighten spleen weight of leukemic mice simultaneously, and also can restrain the expression ER alpha-36 receptor protein in K562 cells in the mode of the concentration dependent. Therefore, the compound of the formula (I) can treat chronic myeloid leukemia.