Abstract: Objective To explore the activity of thioredoxin reductase (TrxR) in chronic myeloid leukemia cell line K562 and the anti-leukemia effect of BBSKE (a novel inhibitor of TrxR) in vitro. Methods The activity of TrxR on K562 cell lineage and fresh bone marrow cell from healthy adult was analyzed by insulin reduction assay. The inhibition of proliferation was measured by CCK-8 assay. The anti-leukemia effect of BBSKE was detected by laser scanning confocal microscope,agarose gel electrophoresis and flow cytometry with Annexin V -FITC/PI staining. Results TrxR activity of K562 cell lineage was significantly higher than that of normal bone marrow mononuclear cells. The apoptosis of K562 cells could be induced at concentrations of 10 μmol/L BBSKE after treated for 24 hours. The typical DNA "ladder" bans were observed by agarose gel electrophoresis. The apoptotic rates of K562 cells were (10.28±2.74) %. Application of 10 μmol/L BBSKE for 48 hours could also induce apoptosis of fresh bone marrow cell from chronic myeloid leukemia patients, and the apoptotic rates were (5.70±0.48) %. Conclusion TrxR activity in chronic myeloid leukemia cells was significantly higher than that of normal cells. BBSKE inhibits the TrxR activity and the proliferation of K562 by inducing apoptosis.It might be a potential medication for chronic myeloid leukemia.