Objective:To investigate the suppression effect on the DNMTs gene by curcumin in pancreatic cancer cell PANC-1 cells and its mechanism  Methods:The PANC-1 cell line was divided into control group, gemcitabine group, curcumin group and combination group. After 48 hours intervention CCK8 assay was to detect the proliferation PANC-1 cells. The expression of DNMT,1, and DNMT,3, mRNA were detected by RT-PCR; the expression of DNMT,1, and Caspase-3 protein were detected by Western blotting  Results:①Compared with gemcitabine group and curcumin group, the combination group inhibited the PANC-1 cell significantly higher(P,<,0.05). ②Compared with the control group, the expression of mRNA of DNMT,1, and DNMT3RT-PCR of gemcitabine group, curcumin group and combination group was lower(P,<,0.05), while the combination group was lower than that of gemcitabine group and curcumin group(P,<,0.05). ③Compared with the control group, the expression of DNMT,1, of gemcitabine group, curcumin group and combination group was lower(P,<,0.05,P,<,0.01), while the expression of Caspase-3 was higher(P,<,0.01), and there was significant difference between the combination group and the groups of gemcitabine and curcumin(P,<,0.05)  Conclusion:The therapy of combination of gemcitabine and curcumin can synergistically down-regulated the DNMT,1, and DNMT,3, gene expression of mRNA,down-regulated the protein expression of DNMT,1,which could via up- regulated the expression of Caspase-3 in the PANC-1 cell line.