Objective：To investigate the effect of T cell factor 3（TCF3） gene silencing on the Wnt pathway transcriptional activity and cell growth and migration in non-small cell cancer A549 cells. Methods：The TCF3 gene was silenced by RNAi technology and used as the experimental group，meanwhile the blank control group and negative control group were set up. The mRNA and protein expression levels were detected by real-time fluorogenic quantitative PCR and Western blot，separately. A TOPflash/FOPflash repoter gene was employed for analysis of the Wnt pathway transcriptional activity. The cell proliferation was detected by CCK-8 assay. The apoptosis and cell cycle were analyzed by flow cytometry. Transwell chamber assay was used to examine the migration potential of A549 cells. Results：Compared with those of blank and negative control groups，mRNA and protein levels of TCF3 were lower in the experimental group. The ratio of TOPflash/FOPflash was lower（P=0.00，P=0.00）. The protein expression of Wnt target C-myc was declined（P=0.00，P=0.00）. The cell proliferation was inhibited. The apoptosis was promoted and the percentage of A549 cells in G0/G1 phase was in－creased（P=0.01，P=0.00）and that in S phase was decreased（P=0.01，P=0.00）. The cell migration ability was reduced（P=0.01，P=0.01）. Conclusion：TCF3 seems to act as a transcriptional activator and promote the malignant biological in lung cancer cells.