The structures of small intestine and pancreas in Andrias davidianus were investigated by electron microscopy. The results were as follows: there was simple columnar epithelium on the intestinal mucosa, the epithelial cells of the intestine in Andrias davidianus bear many long and closely packed microvilli, and contain many mitochondria, rough endoplasmic reticula and lysosome. There were many goblet cell in the intestinal mucosa, in which there were mucous particles, and many microvilli on the free surface. In the acinouscell of pancreas, there were many rough endoplasmic reticula, zymogen granule, mitochondria and ribosome. The electric density of zymogen granule was high, the shape of zymogen granule was rounded, and the diameter of zymogen granule was between 0.3 μm and 0.9 μm. The nucleus, in which there were many metachromatic, was big and long in the centroacinar cell of pancreas, whose cytoplasm was little. There were many microvilli on the surface of the centroacinar cell.