Abstract: Objective 　To const ruct PAVU62Wnt5a/ siRNA expression plasmid and inhibit it s function in H157 cells. Methods 　Human siwnt5a was subcloned into PAVU6 + 27, DH10B E. col. i was t ransformed with the recombinant plasmid, and the ampicillin2resistant clones were identified by double digestion with Hind Ⅲand B am H Ⅰand DNA sequencing. H157 cells were t ransfected with the identified PAVU62si2 Wnt5a and PAVU6 + 27 by Lipofectamine 2000. Results 　The DNA f ragment obtained by double diges2 tion and DNA sequencing showed that siWnt5a was inserted into the PAVU6 + 27 in correct orientation and reading f rame. G4182resistant colonies of H157 cells were obtained. The expression of Wnt5a protein decreased by Western blotting. Conclusion 　PAVU62siWnt5a expression plasmid was const ructed and in2 hibited obviously the expression of Wnt5a in H157 cells, which help to further study the carcinogenesis and metastasis role in non2small cell lung cancer of this protein.