The regional distribution and relative frequency of endocrine cells were studied immunohistochemically in the gastrointestinal tract (GIT) of the Manchurian chipmunk, Tamias sibiricus asiaticus. Six kinds of endocrine cells were identified in this study. 5-hydroxytryptamine (5-HT)-immunoreactive cells were detected throughout the GIT. These cells were observed in moderate numbers in the pylorus, duodenum, jejunum, ileum, fundus, colon, and rectum. Somatostatin- and bovine pancreatic polypeptide (BPP)-immunoreactive cells were also identified throughout the GIT. The former were abundant in the pylorus region while the latter were scattered In ileum and colon. Motilin-immunoreactive cells were rarely detected in the small intestine. A few neurotensin-immunoreactive cells were detected in jejunum, ileum and colon. Also, a few substance P-immunoreactive cells were observed to be restricted to duodenum and jejunum.