The type and distribution of mucous cells stained with AB & PAS (pHAB=2.6) in the intestine tract of silurus asotus (body length 16.4-21.0cm, body weight 33.6-64.3g) have been studied. The development and secreting activity of mucous cells have been investigated using scanning and transmission electron microscopy. The results showed that the mucous cells were dark blue,weak blue and cambridge blue in colour after being stained with AB & PAS(pHAB=2.6); it mainly contained acid mucopolysaccharides; the mucous cells had 3 shapes i.e. capsule-shaped, pear-shaped and cup-shaped. The capsule-shaped mucous cells were distributed in the bottom of the epithelia of the intestine, and its diameter was about 4.40 microm. The pear-shaped mucous cells were distributed in the middle-layer of the epithelia of the intestine, and its vertical range and sidelong was about 6.00 microm and 3.40 microm respectively. The cup-shaped mucous cells were distributed in the top of the epithelia of the intestine, and its vertical range and sidelong was about 12.00 microm and 4.60 microm respectively. The density of mucous cells presented an increasing trend from the anterior(low) to posterior(high) and middle(higher) segment. After derived from bottom cells, the mucous cells evolved gradually from fundus film to exterior of mucous membrane. The mucous cells in developing were filled with plenty of big and small mucosity particulates, and the secreting method of mucous cells was peak serosity secretion.