Abstract： Objective To observe the effects of triptolide(TPL) on the anti-oncogene-APC gene of acute lymphoblastic leukemia cell line Jurkat in vitro. Methods The effects of TPL on proliferation Jurkat cells were assayed by using cell culture, MTT. The effects of TPL on APC gene of Jurkat cells were analyzed by nested methylation specific PCR and RT-PCR. The effects of TPL on the proteinum expression of APC gene were detected by Western blotting analysis. Results Following the treatment of TPL, the cell proliferation rate was degraded as the treatment concentration increased and the culture time extended. The effects were dose and time-dependent. The 48 hour IC50 was 19.7 ng/ml. TPL can reverse hypermethylation of APC gene,and induce the expression of the mRNA and the proteinum. Conclusion Low dose TPL could depress the proliferation rate of Jurkat. The possible mechanism might be its reversing the hypermethylation of APC gene and activiting the expression of APC gene.