Abstract: Objective To investigate the role of nuclear factor Nrf2 in the expression of UGT1A and its isoforms induced by EGCG in colon cancer. Methods We used the technology of RNA interference to block the expression of Nrf2 in HT-29 cell line in vitro, and cultivated the cell line to the phase of logarithmic growth. Using HT-29-siNrf2 cell line we constructed subcutaneous cancer model in the BALB/cA nude mice. Using subcutaneous tumor we constructed orthotopic colon cancer model in nude mice. After having been administrated with low-, medium- and high-dose EGCG for 4 weeks，the orthotopic colon cancer was peeled. The protein expression of Nrf2 of colon cancer was detected by IHC and the mRNA levels of Nrf2, UGT1A, UGT1A8 and UGT1A10 were detected by RT-PCR. Results The body weights of the mice，the inhibition rate of orthotopic colon cancer and the protein expression of Nrf2 detected by IHC had no significant difference compared with those of mice in model group. The mRNA levels of Nrf2, UGT1A, UGT1A8 and UGT1A10 detected by RT-PCR had no significant difference. Conclusion Nrf2 could play a critical role in the expression of UGT1A and its isforms induced by EGCG.