Objective:To explore the relationship between HHIP expression and its hypermethylation in human pancreatic cancer cell lines，so as to provide new insights into the tumorigenesis of pancreatic cancer．Methods: Human pancreatic cancer cell lines BxPC-3，CFPAC-1，PANC-1，AsPC-1 and PaTu8988s were used in the present study. Reverse transcriptase polymerase chain reaction(RT-PCR) and immunocytochemical S-P method were used to detect the expression of HHIP at mRNA and protein levels before and after treatment with 5-aza-2′-deoxycytidine (5-Aza-CdR)，a DNA methyltransferase inhibitor．Methylation-specific PCR (MSP) combined with DNA sequencing were adopted to identify the CpG island methylation of HHIP gene．Results: Expression of HHIP mRNA/protein was absent in the five pancreatic cancer cell lines before 5-Aza-CdR treatment, and re-expressed after treatment with 5-Aza-CdR．CpG island hypermethylation of HHIP gene was observed in the five pancreatic cell lines by MSP and DNA sequencing．Conclusion: Hypermethylation in CpG island of HHIP gene is correlated with the inhibition of HHIP expression in human pancreatic cancer cell lines, and it might play an important role in the development and progression of pancreatic cancer．