A clinical study was carried out on 121 patients(201 sides) who received Caldwell-Luc's operation at the Otolaryngologic Department of Pusan Paik Hospital, Inje Medical college from Jan. 1984, till Dec. 1985. The study includes the patient's past history of illness, physical examination, X-ray findings, gross findings and histopathologic examinations, antral irrigation findings, bacteriological studys and results of operation. The results were as follows : 1) Nasal discharge was the most frequent complaint as 92.6% and nasal obstruction 87.6%, anosmia or hyposmia 22.3%, headache 18.2% in order. 2) More than 5 years group was the most frequent duration of illness as 42.3% and 2-5 years group(35.3%), 6months-1 year group(10.9%), 1year-2years group(6.0%), under 6 months group(5.5%) in order. 3) Nasal polypectomy was the most frequent past history of operation as 8.5% and the percentage of sides that received Caldwell-Luc's operation previously was 3.5%. 4) In the review of X-ray findings, diffuse opacity type was the most frequent finding as 47.2% and diffuse opacity and mucosal thickening type 33.3%, mucosal thickening type 13%, polypoid type 6.5% in order. 5) In duration of the illness related to the X-ray findings, diffuse opacity type was 2 times as more as diffuse opacity & mucosal thickening type in more than 5 years group. Diffuse opacity type and diffuse opacity & mucosal thickening type revealed nearly same frequent in 2-5 years group. Diffuse opacity type was 3 times as more as diffuse opacity and mucosal thickening type in 6months-1 year group. 6) In the physical examination of the nose, nasal discharge and nasal polyp were seen in 13.9%, nasal discharge, middle turbinate hypertrophy and nasal polyp in 10.9%, nasal discharge and inf. turbinate hypertrophy in 10.4%, nasal discharge, nasal polyp and nasal septal deviation in 10.0%, nasal polyp in 10.0% in order. 7) In radiological study related to the physical examination of the nose, nasal polyp and nasal discharge(15.8%), middle turbinate hypertrophy and nasal polyp(11.6%) were seen in order in the diffuse opacity type on X-ray. Nasal discharge and nasal polyp(20.9%) and nasal discharge and nasal polyp and nasal septal deviation(13.4%) and nasal discharge and inferior turbinate hypertrophy(13.4%) were seen in order in the diffuse opacity and mucosal thickening type on X-ray. Nasal polyp(92.3%) was seen in the polypoid type on X-ray. No specific relationship was seen in the mucosal thickening type. 8) The most frequent operation that combined with Caldwell-Luc's operation was transantral ethmoidectomy and nasal polypectomy as 29.4% and transantral ethmoidectomy and middle conchotomy 13.7%, transantral ethmoidectomy 13.2% in order. 9) In the review of antral mucosa, the gross finding revealed 61.2% of simple type and 38.8% of combined type. The hypertrophic type was the most frequent finding in the simple type and hypertrophic and polypoid type was the most frequent finding in the combined type. 10) In radiological studys related to the gross findings of antral mucosa, hypertrophic type, polypoid type, hypertrophy and polypoid type were encountered mostly in case of diffuse opacity type in X-ray finding. Hypertrophic type was encountered the majority in diffuse opacity and mucosal thickening type in X-ray finding. No specific relation was found between mucosal thickening type on X-ray and gross finding. 11) In the view of histopathological findings, mixed type was seen in 55.2%, edematous type in 15.9%, cystic type in 12.4%, infilterating type in 10.0%, fibrous type in 6.4% in order. 12) In radiological study related to the histopathological findings, mixed type was the most frequent in the each diffuse opacity type, mucosal thickening type, diffuse opacity and mucosal thickening type and polypoid type as 66.3%, 46.2%, 43.3%, 53.8%. 13) In histopathological findings related to the duration of the illness, mixed type was the most frequent in the all duration but edematous, cystic and infilterating type were apt to more frequent in more than 2 years groups than other duration. 14) In the postoperation result, the proportion of the improved cases was 86.2%.