Abstract： Objective To investigate the methylation of the promoter region in miRNA in pancreatic cancer cell line PANC1 and normal pancreatic tissue,to discover the miRNA with hypermethylation associated with pancreatic cancer.Methods The genomic DNA of PANC1 and normal pancreatic tissue was extracted,and fractured by ultrasound.Methylation DNA fragments were obtained by 5-methyl of pyrimidine nucleoside antibodies and immunomagnetic beads.The hypermethylation miRNA differentially expressed between PANC1 and normal pancreatic tissue was selected by using methylation DNA chip.BSP ( bisulfite genomic sequencing PCR) and TA clone sequencing was performed for further validation.The genomic DNA of pancreatic cancer cell lines BXPC3,CFPAC1,PANC1 and SW1990 was extracted.The COBRA (combined bisulfite restriction analysis) was used to validate differentially expressed hypermethylation miRNA.Results Eight differentially expressed hypermethylation miRNAs were screened from the DNA methylation chips,then five of them were selected for sequencing.The methylation status of miRNA-615,-663,-663b was significantly higher in the PANC1 than in normal tissues (60.6％ vs 7.6％,88.8％ vs 22.2％,94.4％ vs 13.0％ ) ; the methylation status of miRNA-675 was not significantly different between PANC1 and normal pancreatic tissue (76.0％ vs 100％ ).Due to large error in sequencing,miRNA1826 was excluded.The results of COBRA confirmed all the 4 miRNAs were highly methylated in PANC1 ; except for miRNA-675,other 3 miRNAs were highly methylated in BxPC,miRNA-663,miRNA-663b were highly methylated in CFPAC1,while miRNA-615,miRNA-663 were highly methylated in SW1990.Conclusions Hypermethylation miRNAs were differentially expressed between pancreatic cancer cell lines and normal pancreatic tissue,among them,highly methylated miRNA-663 was possibly associated with pancreatic cancer.