Abstract： Objective To investigate the effects of the silence of teratocarcinoma-derived growth factor-1 ( TDGF-1 ) gene on invasion of human pancreatic cancer cell. Methods Three small interfering RNA (siRNA) targeting for TDGF-1 genes (S1, S2, S3 ) were designed and established, then the gene with the best silencing effects was screened. Human pancreatic cancer cell line PANC1 were transfected by siRNA with different concentrations (3. 125, 6.25, 12.5 nmoL/L), the cells without transfection, and simply treated with liposomes were controls. The expressions of mRNA and protein of TDGF-1 were determined by real time PCR and Western blot assay, respectively. The anchorage-independent growth was examined by clon formation in soft agar, and invasion ability was evaluated by boyden chamber model. PANC1 cells with transfection for 48h were injected into the nude mice to evaluate the invasion ability in vivo. Results The expressions of TDGF-1 mRNA and protein of cells transfected by siRNA were decreased in a dose-and time-dependent manner, which were significantly lower than those in liposomes group. Number of colony formation and transmembrane cell were 19.8 ± 2.2 and 49.8 + 2.6 in the control group, and 5.6 + 1.2 and 8. 1 + 1.1 in the 12.5 nmol/L transfection group. The volumes of tumor 4 weeks after transplation in the control group, liposomes group and the 12.5 nmol/L transfection group were (2.228 ± 0.016 ) cm3, ( 2.186 ± 0.028 )cm3 and ( 0.728 ± 0.023 )cm3. Conclusions TDGF-1 gene silence could inhibit invasion ability of human pancreatic cancer cell PANC1.