It is important and necessary to be aquired with the shape and size of paranasal sinuses because of possible unexpected injury to the surrounding bony walls during the operation. Auther have performed a roentgenological study on the paranasal sinuses and measured various diameters to obtain the normal values of them in materials of 914 normal Korean, and the following results were obtained: 1) The maxillary sinuses appeared after birth in X-ray film. The maxillary sinuses grew rapidly until the age of 2, but thereafter, grew slowly reaching adult size at age of 16 years. 2) The forntal sinuses did not appeared in first and second year after birth, and were identified in 43.8% in the second age group. 3) The number of the chamber and non-development of frontal sinuses would be classified as follow : abscence of both frontal sinuses; 123 cases(13.5%), abscence of right frontal sinuses; 25 cases(2.7%), abscence of left frontal sinuses; 23 cases(2.5%), single chamber of frontal sinuses; 9 cases(1.0%), tripple chamber of frontal sinuses; 3 cases(0.3%). 4) The frontal sinuses increased in size with marked variable growth rate as age increases until the age of 20. 5) Standard deviation of frontal sinuses were large as much as 10mm. 6) The sphenoid sinuses were found at age of 2 and increased in size rapidly until the age of 7, but thereafter, increased in size slowly until the age of 19 and reaching adult size.