Morphology, histology, and histochemical characteristics of the digestive tract of the guirine goby (Rhinogobius giurinus: Gobiidae), collected from the coast of Jeju Island, Korea, were investigated. The digestive tract of R. giurinus, which is a brackish water species, has a short (relative length of gut=0.42), simple, and narrow gut. The gastric glands are well developed in the stomach, but pyloric caeca are absent. The mucosal folds are regularly branched, and the muscularis extern a is thickest in the esophagus, which also contained the most mucus-secreting goblet cells (P<0.05). In R. giurinus, digestive function occurs in the anterior portion of the digestive tract, where mucus protects the tract from the actions of digestive enzymes and functions to activate digestion.