We found that matrine could induce apoptosis of AML cells by collapse of mitochondrial membrane potential (Δψm), release of cytochrome c (cyt c) from mitochondria to cytosol, reduction of the ratio of Bcl-2/Bax, activation of caspase-3, and down-regulation of p-Akt and p-ERK1/2. The gene discussed is MAPK3; the disease is acute myeloid leukemia.