It has been regarded that allergy is one of the important factors concerned to the etiology of nasal polyps. From July 1, 1983 to June 30, 1984, 65 patients of nasal polyp were operated on, and they were analyzed to study the relationship of nasal polyp and nasal allergy, According to their clinical findings, the patients were divided into 3 groups, atopic, aspirin intolerance and intrinsic disease group. The results were as follows : Atopic group was 10 patients(15.4%), aspirin intolerance group 6 patients(9.2%) and intrinsic disease group 49 patients(75.4%). Eosinophilia in nasal secretion noted in 56 patients(86.2%). On skin testing to 65 patients with nasal polyp, positive reactions were obtained in 15 patients(23.1%), and 10 of them was atopic group, one aspirin intolerance group, and 4 intrinsic disease group. Blood eosinophilia noted in 18 patients(27.7%), 4 of them was atopic group(40%) 3 aspirin intolerance group(50%) and 11 intrinsic disease group(22.5%). Blood eosinophilia noted in 5 patients(16.7%) of the 30 paranasal sinusitis patients without nasal polyp and nasal allergy during the same period, who were chosen for control group. In the histological investigation of 64 polyp biopsies, tissue eosinophilia was present in 59 patients(92.2%), squamous metaplasia in 25 patients(39.1), goblet cell infiltration in 24 patient(37.4%) and stromal fibrosis in 18 patients(28.1%).