The X-ray Mucous Membrance Function Test (X.M.F.T) is a method of evaluating the functional capacity of theciliated epithelium of the mucous membrane of the sinus and grade of pathological changes in the tunica propria bydemonstrating the images case by the contrast material (2.5cc of 20% moljodol) injected into the maxillary sinus.This method is essentially different from the conventional simple X-ray studies, because it is able to observepresence and chracter of the contents within the sinus cavity and also to visualize the sinus orifice andextrasinus structures. The authors performed a modified X-ray Mucous Membrane Function Test (central ray wasdirected 15 cauded in erect lateral view) to the patient in whom chronic maxillary sinusitis was suspectedclinically during the period of 7 months from February 1975 to August 1975. The results obtained were as follow ;1. A total number of the patient received X.M.F.T was 90 and sex distribution was 54(60%) males and 36(40%)females. Most of the patient (82.2%) was distributed in 11-40 years of age and peak incidence (40%) was in 11-20years of age. 2. Among a total of 90 patient, bilateral X.M.F.T was performed in 75 patient and unilateral in 15patient. In a sum of 165 maxillary sinuses, 79 cases (47.88%) were on the right side and 86 cases (52.12%) were onthe left side. 3. Takahashi's classification of moljodol X-ray images i.e. A) complete diffusely spread type, B)incomplete diffusely spread type, C) spotted type, D) diffuse localized transitional type, E) localized type, F)scattered type were observed in out cases. But we recognized G) non filling type, which Takahashi did not mention.It was due to severe chronic maxillary sinusitis, extensive malignancy and postoperative state of Caldwell-Lucoperation. Among 7 basic types, incomplete diffusely spread type (31.5%) and diffuse localized transitional type(24.2%) showed higher incidence. 4. In analysing the above 7 basic types, the degree of impairment of the ciliatedepithelium of the sinus mucosa was severe in A,B,C,D,E,F,G in order. 5. The sinus orifice was open in A,B typebeing mild sinusitis but close in D,E,F,G type being moderate and severe sinusitis. 6. The incidence ofinvolvement of the other sinuses were higher in D.E,F,G type than in A,B,C type and the ethmoid sinus anatomicallylocated near to the maxillary sinus showed higher incidence than the other frontal and sphenoid sinuses. It couldbe emphasized that X,M,F,T is a useful method for early detection of maxillary cancer and also could indicate atherapeutic approach to each type of sinusitis to E,N,T doctor.