Abstract: OBJECTIVE： To study the expressions of Nrf2 and NQO1 mRNA, Nrf2 protein by coal tar pitch (CTP) extract. METHODS： BEAS-2B cells were treated with different concentrations of CTP extract (0.00, 1.25, 2.50, 5.00, 10.00 μg/ml) for 24 h. Total cell RNA and protein were extracted. The expressions of Nrf2 and NQO1 mRNA and Nrf2 protein were measured by the reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. RESULTS：The expressions of mRNA and protein of Nrf2 among test groups(1.25－5.00 μg/ml) were significantly lower than those in the control group. With increasing concentration of CTP extract, the expressions of Nrf2 and NQO1 mRNA, Nrf2 protein increased. However, the mRNA and protein of Nrf2 decreased in the CTP 10.00 μg/ml group. CONCLUSION： When the concentration of CTP extract was at a 1ow 1eve1，the expression of Nrf2 increased in parallel with the CTP extract concentration. So Nrf2 might induce the gene expression of NQO1, enhancing the antioxidant ability of BEAS-2B cells.

Key words: coal tar pitch extract, BEAS-2B, NF-E2-related factor2, NQO1