The conventional histochemical stains were used to study the properties of mucosubstances of the intestine in four teleostean species, i. e., Agramus agramus, Inimicus japonicus, Epinephelus chlorostigma, and Helicolenus dactylopterus, all belonging to the order Perciformes. The following methods were used; periodic acid Schiff (PAS), alcian blue (AB) pH at 2.5, AB pH at 1.0, AB pH at 2.5-PAS, and aldehyde fuchsin (AF) pH at 1.7-AB pH at 2.5 stain. The mucosal folds of intestines show differences in species and regions. Widely distributed in all portions studied, goblet cells situated between cylinderical epithelial cells are round or ovoid in shape. They were most densely distributed in distal intestine. In the middle and. distal intestine of Epinephelus chlorostigma and all regions of intestines of Agramus agramus, Inimicus japonicus, and Helicolenus dactylopterus, the presence of both acidic and neutral mucin was confirmed. The property of acidic mucosubstance was sialomucin. Neutral mucin was only encountered in the proximal intestine of Epinephelus chlorostigma. The amount and property of mucin showed differences in species and regions. In the distal intestine of Inimicus japonicus, the amount of acidic mucin is similar to that of neutral mucin. In all regions of intestine of Agramus agramus, proximal and middle intestine of lnimicus japonicus, middle and distal intestine of Epinephelus chlorostigma, and distal intestine of Helicolenus dactylopterus, acidic mucin occured more frequently than neutral mucin. The proximal and middle intestine of Helicolenus dactylopterus have more neutral mucin than acidic mucin.