It has been known that the intestinal epithelial cell is characterized by a rapid cell turnover and by a gradient of differentiation from crypt to villas. The present study was undertaken to clarity the effect of diet on the migration and the maturation of the intestinal epithelial cells. The transit time from the crypt to the extrusion zone at the villus tip was determined with tritiated thymidine. To study the maturation of the cells the distribution of the terminal digestive enzymes, maltase [EC 3. 2. 1. 20] and leucylnaphthylamidase [EC 3. 4. 1. 1], along the villus and crypt was analyzed quantitatively. And total activities of the same enzymes were assayed also in the mucosal homogenates. It was observed that the decrease in the migrating speed of villus cells was brought by energy restriction and the decrease in the migrating speed was associated with an increase of the enzyme activities in the upper zone of villus. And the result was that the intestinal epithelial cells which decrease in migrating speed by dietary restriction become more mature on the upper villus than those with unrestricted control.