This study was performed for the purpose of clinicopathological study of the chronic maxillary sinusitis. The mucous membrane of maxillary sinuses in 162 cases that received Caldwell-Luc's operation during the period from Jan. 1978 to Dec. 1979 in Dept. of Otolaryngology, Ewha Womans University Hospital. The results were obtained as follows; 1) In the age incidence, the highest incidence was noted between 15-19 years of age(73 cases, 45.6%). In sex distribution, 64 cases(39.5%) were males and 98 cases(60.5%) were females, and the ratio between male and female was about 1 : 1.5. 2) The pathological classification(according to Schall's classification) revealed mixed type(72 cases, 44.5%), fibrotic type(37 cases, 22.8%) edematous type(28 cases, 17.3%), infiltration type(13 cases, 8%), and cystic type(12 cases, 7%) in 162 cases. 3) The most frequent inflammatory type was grade II(47 cases, 65.3%) in mixed type, grade II(17 cases, 45.9%) in fibrotic type, grade III(16 cases, 57.1%) in edematous type, grade III(9 cases, 69.2%) in infiltrative type and grade II(8 cases, 66.7%) in cystic type. 4) In the relation of type of mucous membrane to nasal polyp grade II in mixed type(9 cases, 36%) is most frequent among 25 cases. 5) In the relation of type of mucous membrane to duration 1 to 3 years duration(45 cases, 27.8%) is most frequent. 6) Chief cormplaints of chronic maxillary sinusitis were nasal stuffiness(43.7%), postnasal drip and headache in order.