Abstract： Objective To investigate the expression of nuclear factor erythroid-2 related factor 2 (Nrf2) gene in chronic myeloid leukemia (CML) and explore its relationship with clinical characteristics and thioredoxin reductase (TrxR).Methods The expressions of Nrf2 and TrxR genes in bone marrow cells and K562 cells were analyzed in 30 bone marrow preparations of CML patients in different phases,including 20 in chronic phase,3 in accelerated phase,7 in blastic phase by real-time quantitative polymerase chain reaction.Ten health subjects were served as normal controls.Results The relative quantitation expression of Nrf2 and TrxR mRNA were 5.601±1.069 and 9.017±2.398 in chronic phase,1.698±0.349 and 5.590±1.015 in accelerated phase,1.252±0.807 and 5.050±1.469 in blastic phase,1.377± 0.344 and 1.867±0.977 in normal controls.The expressions of both Nrf2 and TrxR mRNA in CML had significant differences from those of the normal controls (x2 =14.680,P =0.002,x2 =8.271,P =0.041).The expression of Nrf2 mRNA in accelerated phase,blastic phase group showed no significant difference (Z =0.011,P =0.496),but lower than that in chronic phase group (Z =2.155,P =0.016,Z =2.534,P =0.006).The difference between the first visit and post-treated group was significant (Z =2.015,P =0.022).The expression in K562 cells and normal controls had significant difference (Z =1.898,P =0.029).In CML patients,the expression of Nrf2 was positively correlated with that of TrxR (r =0.738,P =0.037).Conclusion The expression of Nrf2 gene is higher in the first visit group of CML than that in the other groups,and is decreased after therapy,which may be the molecular marker predicting the progress of CML.Nrf2 mRNA expression level is correlated with TrxR.