Human intestines were studied enzyme histochemically. Enzymes used were alkaline phosphatase, acid phosphatase, beta-esterase, aminopeptidase, and beta-glucuronidase as hydrolytic enzymes and succinic dehydrogenase, lactic dehydrogenase, malic dehydrogenase, alpha-glycero-phosphate dehydrogenase, beta hydroxybutyric dehydrogenase, glucose-6-phosphate dehydrogenase and isocitric dehydrogenase as oxidative enzymes. All of these enzymes showed strong activities in surface of villi of small intestines. Alkaline phosphatase and aminopeptidase showed weak or no activity in large intestines, but strong one in surface of villi. In crypts acid phosphatase activity was rather strong in the base and it seemed to have connection with Paneth's cells. Brunner's glands showed moderate acid phosphatase activity. Most oxidative enzymes were kept in columunar epithelium while others such as lamina propria, tela submucosa, muscle layer and iymph nodules had weak activities for these elnzymes. Succinic dehydrogenase and most NAD dependent dehydrogenases showed stronger activity in the base of crypt, It needs farther studies to conclude whether this finding corresponds with the proliferating place of epithelium or with paneth's cells. All enzymes were weak or slight in appendix. In anus, srypt cell of transitional part between columunar and squamous epithelium had strong oxidative enzyme activities.