Objective To observe the apoptotic effect of cardamonin on K562 cells and its relationship with the expressions of PTEN, p-Akt, NF-κB and Bcl-2. Methods K562 cells were treated with cardamonin for 48 h, and the following tests were performed: (1) The cell morphology was observed by light microscopy.(2)IC50 of the K562 cells was dtermined by MTT test.(3)The apoptosis rate was detected by flow cytometry. (4) The expressions of Bcl-2 and Bax mRNA were detected a by RT-PCR. (5) The expressions of PTEN, p-Akt, NF-κB and Bcl-2 proteins were detected by Western blot. Results Obvious apoptosis was observed in the K562 cells after treated with cardamonin for 48 h. MTT assay indicated that the proliferation of K562 cells was obviously inhibited in a dose-and time-dependent manner. Comparing with the blank group, the early apoptosis rate and expression of Bax mRNA were significantly increased. At the same time, the expression of Bcl-2 mRNA was significantly decreased. All of them presented a dose-dependent manner. The expression of PTEN obviously increased with the increasing dose of cardamonin and the expressions of p-Akt, NF-κB and Bcl-2 were decreased. Conclusions Cardamonin promotes the apoptosis in K562 cells in a dose-dependent manner by increasing the expression of PTEN and decreasing the expressions of p-Akt, NF-κB, and Bcl-2.