Abstract: Objective To explore the down-regulation effect of transforming growth factor-β1 (TGF-β1) on the expression of vascular endothelial growth factor (VEGF) in bladder cancer cell line EJ cell strain. Methods The siRNA expression vectors of TGF-β1 gene were constructed, the highest inhibition target sequence was screened and selected by Real time-PCR and ELISA, and then the vectors were transfected into EJ cells, the expression level of VEGF mRNA was detected by Real time-PCR. Results TGF-β1 targeting expression vectors were successfully constructed, Real time-PCR and ELISA screened the highest inhibition target sequence (the lowest expression level of TGF-β1mRNA was 0.92±0.19; ELISA result was 50.08±5.85). The relative expression level of VEGF mRNA in TGF-β1 siRNA group was the lowest, indicating that the expression of VEGF was decreased by silencing TGF-β1 gene. Conclusion Inhibition of TGF-β1 gene expression could down regulate the expression of VEGF in bladder neoplasm.