As a candidate for progenitor of endocrine cells, pancreatic duct epithelium displays more and more importance of differentiation potential to insulin-producing cells. Some cell markers such as pdx-1, nkx6.1 expressed in pancreatic islet development have also been found in duct. The maf family, which is a subgroup of the basic leucine zipper(bZip) transcription factors with homology to the v-Maf oncoprotein, the founding member of the Maf family, which was originally identified in the genome of the AS42 chicken musculoaponeurotic sarcoma retrovirus in 1989, has been involved in pancreatic research recently. Members of Maf family, mafa, mafb, c-maf, which have been reported to be regulators of tissue-specific gene expression and cell-differentiation in a wide variety of tissues, are all expressed in islet and regulate insulin expression as well as islet development. Whether these genes are expressed in duct remains unclear and demands further investigation. Islet, duct and exocrine tissues were acquired by laser-capture microdissection from mouse pancreatic section, followed by real-time PCR to quantitate the target genes expression. Mafa, mafb, c-maf were all detective in duct and islet but none was in exocrine tissue. In addition, c-maf mRNA level in duct was higher than islet(0.300±0.018 vs 0.796±0.173, P < 0.05), however, there was no difference in mafa and mafb mRNA level between islet and duct. The expression of mafa, mafb, c-maf in pancreatic duct epithelium, gives more support to not only the roles of the three genes in endocrine development, but also the potential of converting duct epithelium to endocrine cells. Moreover, the higher expression of c-maf in duct than islet suggests that down-regulation of c-maf might help to differentiation and mature of endocrine cells.