Objective To investigate the effect of B cell translocation gene 1 (BTG1) overexpression onproliferation and invasion of pancreatic cancer cells and to elucidate the mechanism. Methods The expression of BTG1mRNA and protein in the human pancreatic cancer cell lines, PANC-1, AsPC-1 and BxPc-3, and in the normal pancreaticductal epithelial cell line, H6C7, was determined by qRT-PCR and Western blotting, respectively. BxPc-3 cells culturedin vitro were divided into a control group (untransfected), pcDNA3. 1 group (transfected with an empty pcDNA3. 1 vector)and BTG1 group (transfected with pcDNA3. 1-BTG1 overexpression plasmid). At 48 h after transfection, the transfectioneffects were examined by qRT-PCR and Western blotting. Cell proliferation, cell cycle distribution and invasion ability ineach group were measured by MTT assay, flow cytometry and Transwell chamber, respectively. The expression of cell cycleprotein D1 (cyclin D1), cyclin B1, matrix metalloproteinase 2 (MMP-2) and MMP-9 was determined by Western blotting.Results Compared with the H6C7 cells, the expression levels of BTG1 mRNA and proteins in PANC-1, AsPC-1 andBxPc-3 cells were significantly decreased ( P < 0. 05), and the most significant difference was observed in the BxPc-3 cells.Compared with the control group, the proliferation, invasiveness, the percentage of cells in S phase and the proteinexpression of cyclin D1, cyclin B1, MMP-2 and MMP-9 in the BTG1 group were significantly decreased, while thepercentage of cells in G0/ G1 phase was significantly increased ( P < 0. 05). There was no significant difference between thepcDNA3. 1 group and the control group in cell proliferation, invasiveness, cell cycle distribution and expression of theabovementioned proteins ( P > 0. 05). Conclusions BTG1 overexpression inhibits the proliferation and invasion ofpancreatic cancer cells, and its mechanism may be associated with downregulation of cyclin D1, cyclin B1, MMP-2 and MMP-9 protein expression.