Background/Aims: The aim of this study was to examine pancreatic exocrine function in the ra treated with raw soybean (RS). Methods: There were six groups as follows: Group 1 was the contro group. Group 2 and 3 were given RS diet for 1 and 2 weeks, respectively. Group 4, 5 and 6 wer given normal chow diet for 5, 7, and 14 days, respectively, after RS diet for 2 weeks. Thei pancreatic juice was collected in basal and cholecystokinin (CCK, 50, 100, and 200 pmol ·kg-1 ·hr-1 stimulation period. Apoptosis was confirmed with TUNEL stain. Results: Feeding RS significantly increased wet weight of pancreas and basal pancreatic exocrine secretion. When the diet was changed to a normal chow diet, the pancreas was regressed and basal seretion was decreased. The responses of pancreatic flow to CCK stimulation in both grown and atrophic groups were not different from that of the control. However, pancreatic amylase response to CCK in both groups was significantly reduced. Apoptosis was increased in atrophic groups. Conclusions: RS administration increased pancreatic exocrine secretion, but the secretion was decreased after changing to normal diet Pancreatic amylase response to exogenous CCK stimulation in both grown and atrophic states was significantly reduced. (Kor J Gastroenterol 1999;33:395 - 403)