Objective：To investigate the biological effects of TPM3 in rat pancreatic cancer cells and related molecular mechanisms during tumorigenesis. Methods：（1）Totally 70 SD rat were randomly divided into three groups：operation group（n=40，DMBA was di－rectly implanted into the pancreatic parenchyma），sham operation group（n=15，the pancreatic parenchyma was dissected，but no DMBA was implanted），blank control group（n=15，received no treatment）. An animal model with pathological characteristics of human pan－creatic cancer was established. （2）TPM3 was verified by immunohistochemistry. （3）Combination of mechanical separation and en－zyme digestion and separation was used to get the rat pancreatic cancer cells，and then the expression of TPM3 in rat pancreatic can－cer cells was knocked down by transfecting TMP3-siRNA into cancer cells. Expression of TPM3 was confirmed by RT-PCR. （4）Tran－swell membrane assays were used to examine migration and invasion potentials. Colony formation assay was used to test cell growth capacity. Results：（1）37.83%（14/37） rats in model groups generated pancreatic carcinoma with pathologically verification. （2）The in－creased level of TPM3 protein in rat pancreatic cancer was further confirmed by immunohistochemical（92.8%）. （3）RT-PCR result showed that，compared with other groups（liposome group（0.45±0.02），negative control group（0.45±0.02），blank control group（0.43±0.02）），the ratios of relative TPM3 expression in inter－ference group were significantly reduced（0.31±0.02）（P<0.05）. （4）Silencing of TPM3 leaded to significantly inhibited capaci－ties of invasion（161.63±4.94 and 39.7±1.40 respectively） and migration （206.87±4.21 and 67.27±1.76 respectively） in rat pancreatic cells，and colony formation of PC cells was suppressed after TPM3 knockdown（51.5±2.327 and 5.9００±0.767 respectively）（P＜0.05）. Conclusion：Overexpression of TPM3 will increase poten－tials of invasion or migration of cancer cells during tumorigenesis.