A total of 30 cases of nasal polyp was operated at the Department of Otolaryngology, National Medical Center from March to July 1987. The 30 cases were compared for tissue mast cell, serum IgE, and peripheral blood eosinophils with the 10 cases of control group. The results obtained were as follows : 1) The age distribution showed the highest incidence in 3rd decade, and 73.3% between 2nd and 5th decade group. 2) The sex ratio, male vs female has no significant difference. 3) Histopathologically, the tissue mast cells were more abundantly found in polyps than in control. 4) There was no intimate correlation between increased serum IgE and distribution of tissue mast cells. 5) There was no intimate correlation between increased peripheral blood eosinophils and distribution of tissue mast cells. As above results, it seems that nasal polyp is considered to be associated with allergy, but each the serum IgE and peripheral blood eosinophils can not be an indicator of allergy in nasal polyp.