Chronic paranasal sinusitis is one of the most prevalent diseases in the field of otolaryngology. Fourty-six histopathologic specimens from maxillary sinus were classified into infiltrating, edematous, fibrous and mixed type by hematoxylin and eosin staining, and examined mast cells by Toluidine Blue staining and IgE by peroxidase-antiperoxidase method immunologically. The aim of this study is to find out the distribution of mast cells and IgE-bearing cells in the sinus mucosa, to compare the interrelation between the count of mast cells and IgE and histopathologic type of the sinus mucosa. The following results were obtained. 1) In infiltrating type, most of mast cells were identifed in stromal tissue and IgE-bearing cells were largely located in superficial stromal tissue. 2) In edematous type, mast cells were predominantly distributed in superficial stromal tissue, and IgE-bearing cells were predominantly distributed in superfial stromal tissue. 3) In fibrous type, mast cells were seen in stromal tissue, and no IgE was identified. 4) In mixed type, mast cells and IgE-bearing cells were distributed in stromal tissue. 5) Mast cells were distributed in stromal tissue of all types, and statistical difference was found between infiltrating and edematous type in superficial stromal tissue(p<0.05). 6) In stromal tissue of edematous type, mast cells and IgE-bearing cells were demonstrated than any other type, and a correlation between mast cells and IgE was found. 7) In glands and vessels, mast cells and IgE were not different distinctly among four types.