The purpose of this study was to examine the effect of ethanol on apoptosis of human promyelocytic leukemia cell line HL-60 cells and search for a possible reason for reduced PMNs, monocytes, lymphocytes in the blood of alcoholics. Human promyelocytic leukemia cell line HL-60 cells was used as a model of apoptosis, with ethanol being the interfering factor. Qualitative and quantitative detection was done by both electron microscopy and flow cytometry. Compared with the control treatment of HL-60 cells with ethanol at 50, 100, 150, 200, 250 mmol/L for 3 days increased apoptotic cells significantly (P < 0.01), and apoptosis was dose-dependent for ethanol. It suggest that ethanol can induce apoptosis of HL-60 cells. So as far as reduced PMNs, monocytes, phagocytes and lymphocytes of alcoholics are concerned, ethanol-induced apoptosis may well be an important reason.