The knowledge of normal tracheal morphology is helpful during endotracheal intubation for anesthesia as well as detecting tracheal and paratracheal disorders. Tracheal measurement by simple X-ray is not accurated due to image imagnification and overlapping of the shoulders in the lateral profection. CT however is highly accurate to measure the normal tracheal morphology and paratracheal anatomy. The study was undertaken to obtain standard values of normal Korean tracheas. Healthy cases of 50 males and 50 females who had no neck and mediastinal pathology or respiratory dif-ficult were selected. The trachea was measured by CT. The results were as follows; 1. Tracheal lengths were 126 . 1mm(SD 11.6) in males and 116.omm (SD 8.4) in females. 2 AP diameters of trachea were 18.9mm (SD 2.1) in males and 15.5m (SD 1.3) in females. The transverse diameters were 17.7mm (SD 1.9) in males and 15.3mm (SD 1.2) in females. 3. Tracheal cross-sectional areas were 288mm2 (SD 54)in males and 204mm2 (SD 31) in females. Mean cross-sectional area 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 shae was most common at the level 1, The C-shape was most common at the level 2 and 3, horizontal oval or D-shape were more common at the level4.