Abstract:RegIIIγ, a kind of novel antimicrobial protein with multiple functions, such as antibacterial, antiinflammation, modulation of immune responses, and stimulation of cell proliferation, is highly expressed in intestine and skin of mammalian. To investigate the expression pattern and cell type, the mRNA and protein expression levels of RegIIIγ in neonatal piglets’ intestine from 05 weeks were analyzed by realtime PCR and western bolt, and cells expressing RegIIIγ were determined by immunohistochemistry. PCR and western blot analysis showed that there were no significant differences of RegIIIγ mRNA and protein among the duodenum, jejunum, and ileum, and the mRNA and protein levels exhibit an increase trend with the development except for a decrease of mRNA after weaning. Immunohistochemistry assay revealed that RegIIIγ mainly expressed in absorption enterocytes and Paneth cells.