The knowledge of normal tracheal morphology is helpful during endotracheal intubation for anesthesia as wellas detecting tracheal and paratracheal disorders. Tracheal measurement by simple X-ray is not accurate due toimage imagnification and overlapping of the shoulders in the lateral projection. CT, however, is highly accurateto measure the normal tracheal morphology and paratracheal anatomy. The study was undertaken to obtaine standrdvalues of normal Korean tracheae. Healthy cases of 50 males and 50 females who had no neck and mediastinalpathology or respiratory difficult were selected. The results were as follows: 1. Tracheal lengths were 126.1mm(SD11.6) in males and 116.0mm (SD 8.4) in females. 2. AP diameters of trachea were 18.9mm(SD 2.1) in males and 15.5mm(SD 1.3) in females. The transverse diameters were 17.7mm(SD 1.9) in males and 15.3mm(SD 1.2) infemales. 3. Tracheal cross-sectional areas were 288 mm2 (SD 54) in males and 204mm2 (SD 31) in females. Mean cross-sectionalarea of level 4 was greater in 16.6% than that of level 1. 4. Tracheal cross-sectional areas and diameters were dependent on sex but not on weight and height. And cross-sectional areas and AP diameters were positively correlated with age in male. 5. The shape of the trachea showed that the ovoid shape was most common at the level1, the C-shape was most common at the level 2 and 3, horizontal oval or D-shape were more common at the level 4.