Abstract: Objective The effects of TPT on the induction of apoptosis of leukemia cells and the regulation of c-myc in mRNA and protein level. Methods RT-PCR method was adopted to examine the expressions of the genes and immune histochemistry for the proteins of c-myc in HL-60 cells treated with TPT of optimal concentration and time. Results After HL-60 cells by TPT of 0.15 μmol/L for 12 h, the expression of c-myc mRNA decreased markedly assayed by RT-PCR. There was a significant difference between the TPT group and the control group(0.17±0.03 vs 1.11±0.25, P <0.05), expressive c-myc protein decreased assayed by evidently immunohistochemistry. The percentage of positive cells expressing c-myc protein was a significant difference between the TPT treated group and the control group (19.67 % vs 68.33 %, P<0.05). Conclusion TPT down-regulates endogenic c-myc mRNA and c-myc protein in HL-60 cells.