Abstract: Objective 　To observe the inhibitive effect, the apoptosis and bcl-2 expression of K562 cells with etoposide and hyperthermia. Methods 　The working concent ration of etoposide against K562 cells was determined by MTT assay. Then hyperthermia and chemotherapy were used singly or concurrently and the cell survival rates were obtained at 48h. The inhibitive effect was evaluated by MTT assay. The apoptosis rates and bcl-2 expression of K562 were determined at 48h by flow cytomet ric. Results 　The concent ration of etoposide was defined as those of IC50. The 40 ℃,42 ℃hyperthermia of 60min showed obvious inhibition to K562 cells ( P < 0. 01), etoposide chemotherapy or hyperthermia both obviously inhibited the growth of K562 cells ( P < 0. 01), etoposide chemotherapy combined with hyperthermia showed obvious effect to K562 cells. According to flow cytomet ric analyses, the treatment of hyperthermia and etoposide used alone or concurrently could obviously increase the apoptosis rates and down-regulate of bcl-2 expression of K562 cells. Conclusion 　Etoposide chemotherapy combined with hyperthermia showed obvious inhibitive effect to K562 cells. The effect can increase the apoptosis rates and down-regulate of bcl-2.