The anatomical structures of the paranasal sinuses have great variations between individuals, so the surgeons should be familiar with normal structures and variations of the paranasal sinuses in order to make accurate diagnosis of the diseases of the paranasal sinuses and to perform sinus operations without complications. In this respect various radiological studies have been tried. The authors have carried radiological measurements on the paranasal sinuses of 107 normal Korean adults in order to get topographic anatomical data and to manage the patients with sinus problem safely and effectively. The results were as follows : 1) The area of the maxillary sinus was 8.9±3.6cm²;9.9±3.6cm² in male and 7.3±3.0cm² in female. 2) The angle of roof the ethmoid sinus was 65.3±17.6˚;65.6±18.2˚ in male and 64.8±16.8˚ in female. 3) In types of roof of the ethmoid sinus, the most common type was type B(47.2%). 4) The width of the olfactory fissure was 4.9±2.5mm;4.9±2.6mm in male and 4.7±2.5mm in female. 5) The height of the crista galli was 16.4±4.3mm;16.7±4.2mm in male and 15.8±4.5mm in female. 6) The angle of anterior lamina papyracea was 16.9±6.2˚;16.5±6.2˚ in male and 17.5±6.5˚ in female. And that of the posterior lamina papyracea was 28.4±6.3˚;27.6±6.7˚ in male and 29.6±5.3˚ in female. 7) The area of the frontal sinus was 4.6±3.5cm²;5.1±3.7cm² in male and 3.7±3.0cm² in female. 8) In types of pneumatization of the sphenoid sinus, the most common type was sellar type(52.3%).