The protein expression of bcl-2, bax, Fas/Apo-1 in 19 cases of acute myeloid leukemia (AML) were investigated by Western blot and ApAAp techniques. High expression of bcl-2 protein was found in most of the AML cases, and some of the cases expressed Fas/Apo-1 and bax. High expression of bcl-2 protein was associated with a bad clinical prognosis and a poor response after intensive chemotherapy. Bax seemed to coexpress with bcl-2 and so appeared to be a bad prognostic factor instead of a good one. The expression of Fas/Apo-1 was inversely correlated with bcl-2 and seemed to be a good prognostic factor which may reflect the relative homeostasis of apoptotic pathway. It is concluded that apoptosis-induced pathways in AML often exhibit disturbance features. Coregulation of bcl-2, Bax and Fas/Apo-1 genes formed the apoptosis-induced pathway, which is the biological factor affecting response to chemotherapy.