The epithelia of the nasal cavity and the paranasal sinuses consist of pseudostratified ciliated columnar epithelia and it was reported that the density of the epithelial cells were different by the locations. From these studies, it was suggested that there were some differences in the physiologic functions by the locations. If the density and the distribution of the epithelial cells are studied by the locations, physiology of the nasal cavity and the paranasal sinuses may be inferred. For quantitative measurement of density and distribution of various epithelial cell types in maxillary sinus mucosa of health rabbits, the specimens from four sites(anterior wall, medial wall, lateral wall, and near the ostium) of five rabbits were obtained and examined using the light microscope and the scanning electron microscope. The results were as follows ; 1) The density of ciliated cells, by the percentage of surface occupied by the cells, was 93.71±2.56% in the anterior wall, 93.83±2.01% in the medial wall, 95.01±1.58% in the lateral wall, and 79.93±8.90% near the ostium. The density of the ciliated cells near the ostium was significantly lower than the densities(average 94.18±2.10%) in the other walls of the maxillary sinus(p<0.05, Kruskal-Wallis test). 2) The density of goblet cells, by the percentage of surface occupied by the cells, was 6.29±2.56% in the anterior wall, 6.17±2.01% in the medial wall, 4.99±1.58% in the lateral wall, and 20.07±8.90% near the ostium. The density of goblet cells near the ostium was significantly higher than the densities(average 5.82±2.10%) in the other walls of the maxillary sinus(p<0.05, Kruskal-Wallis test). 3) The density of goblet cells, by the absolute number of cells per mm², was 16,928±5,333 cells/mm² in the anterior wall, 15,611±3,910 cells/mm² in the medial wall, 12,038±1,475cells/mm² in the lateral wall, and 43,765±19,923 cells/mm² near the ostium. The density of goblet cells near the ostium was also significantly higher than the densities(average 14,859±4,320cells/mm²) in the other walls of the maxillary sinus(p<0.05, Kruskal-Wallis test). 4) No non-ciliated cells were observed in the maxillary sinus. From the above results, it was concluded that dense goblet cells near the ostium might make the secretion, which reached the ostium by the mucociliary action of the numerous cilia, drained easily into the nasal cavity by humidifying relatively stronger air stream near the ostium.