Objective To investigate the expressions of β-catenin and lymphoid enhancer factor 1(LEF1) mRNA in acute leukemia(AL)and their correlation. Methods Real-time PCR was used to examine the expres-sions of β-catenin and LEF1 mRNA in 62 de novo acute myeloid leukemia(AML)patients,23 de novo acute lymphoblastic leukemia(ALL)patients,20 controls and 4 kinds of cell lines:K562,HL-60,THP-1 and Raji. Results The expression level of β-catenin in AML group was significantly higher compared with the control group,but LEF1 mRNA expression in AML group was significantly lower than that in the control group (P <0.05). The expression levels of β-catenin and LEF1 mRNA were all significantly higher in ALL group compared with the control group (P < 0.05). There were significantly positive correlations between β-catenin and LEF1 mRNA expressions both in AML and in ALL groups(P<0.05). Among the three AML cell lines,THP-1 cell had the highest β-catenin mRNA expression and the lowest LEF1 mRNA expression,and the expression tendencies of these two genes in THP-1 cell line were in accordance with those in AML patients. Conclusions Activation of Wnt/β-catenin pathway happends in AL patients and β-catenin/LEF1 may play a role in leukemogenensis of ALL.