Norcantharidin (NCTD) is the demethylated form of cantharidin, which is the active substance of mylabris, and is known to have anticancer potentials. The aim of this paper was to assess the apoptosis-inducing effect of NCTD on HL-60 cells. Methods. The effects of NCTD were detected by flow cytometer on the cell toxicity, cell cycle, and apoptosis of HL-60 cells cultured in vitro. Results. After 48-hour treatment with NCTD, the growth of HL-60 cells was inhibited significantly. The summit of apoptosis appeared after 24 hours. The percentage of the cells in G1 phase decreased and then increased in S and G2 + M phase, while the S and G2 + M phases were blocked after treatment with 5, 10, and 50 μmol/L NCTD for 24 hours. Conclusions. NCTD can induce the apoptosis of HL-60 cells and inhibit the fissiparism, and the domino effect was obviously correlated with the time and dosage.