Abstract: The histological structure and types of mucous cells in the digestive tracts (i.e., tongue, esophagus, stomach and intestines) of Rhabdosargus sarba were observed and analyzed by using HE and AB-PAS (alcian blue and periodic acid schiff's reation) conbined staining. Results showed that R.sarba has a broad oropharyngeal cavity and different type of teeth. The stomach is divided to three parts which are cardiac stomach, stomach caeca and pyloric stomach. The cardiac stomach has the most gastric pit and gastric gland while stomach caeca has the thickest wall. There are abundant mucous membrane pleats in the whole intestine. R.sarba has 8 to 10 pyloric caecas which structure is similar to anterior intestine. The dividing lines of liver lobules are dim. There are plenty of tubular tissue in hepatopancreas. Pancreatic acini and pancreatic islets distribute around main veins, acinar cells being stained into navy blue are closely arranged. According to AB-PAS,4 types of the mucous cells in the digestive tracts of R.sarba were observed: typeⅠwasred, typeⅡ was blue, type Ⅲ was purple reddish, type Ⅳ was blue purple. Only a small quantity of type Ⅱ and type Ⅲ mucous cells were found occasionally in stomach. Most of mucous cells in the other digestive tracts were of type Ⅲ and type Ⅳ. The density of the mucous cells in the intestine was related to the functions of the different segments in the digestive system.