28.13 ug/ml, respectivly. And the appropriate concentration of cytochrome C in apoptosis was 9.38ug/ml-22.5 ug/ml. The appropriate interactive time was 24 hour. Conclusions: A certain concentration of cytochrome C can induce apoptosis of HL-60 cells. Being a kind of apoptosis inducers of lukemic cells, cytochrome C may be used widely in clinical therapy in the future. " v:shapes="_x0000_s1026">1034