To explore the inhibitory effect of thalidomide combined with interferon (IFN) on the human acute myeloid leukemia cell line Kasumi- 1 and its mechanism.The inhibitiory effect of Kasumi- 1 cells by thalidomide, interferon or combination was detected by CCK- 8 method, the apoptosis by flow cytometry, the expression of apoptosis related proteins by Western blot, vascular endothelial growth factor (VEGF) concentration in culture supernatant by ELISA.Thalidomide inhibited the proliferation of Kasumi- 1 in a dose- dependent manner from 50 μg/ml to 500 μg/ml with an IC₅₀ of (451.