Determination of several normal values were carried out in healthy 1805 cases of Korean adults, 1436 cases of male and 369 cases of female, by the drawing and calculation on chest roentgenogram. In many instances, the change of normal values provides an important clinical values, and often is decisive to evaluate the diagnosis, treatment and prognosis of pulmonary, cardiac and mediastinal disease. The results are as follows: 1) Height of both lung fields. : Male Female Total Right 22.1cm 19.9cm 21.6cm Left 23.7cm 21.2cm 23.2cm It show about 2.0cm larger in male than female and about 1.6cm larger on left side than right. 2) Transverse diameter of thoracic cage and heart, and coefficiency between above two values. (C/T ratio) Male Female Total Thoracic age 29.9cm 27.7cm 29.4cm Heart 12.7cm 12.6cm 12.7cm C/T 0.43 0.44 0.43 Thoracic cage reveals 2.0cm larger in male than female. 3) Thoracic vertebral level of bifurcation. Male Female Total T-4 2.7% 1.3% 2.4% T-5 70.9% 74.3% 71.6% T-6 26.4% 24.4% 26.0% Most common level of bifurcation in T-5, and next T-6 in both sex. 4) The angle of carina. Male Female Total Right bronchus 29.9 30.6 30.0 Left bronchus 36.4 36.9 36.5 Carina 66.2 67.4 66.5 It shows also about 6.5 degree larger in left side than right. 5) Transverse diameter of trachea and bronchus. Male Female Total Trachea 1.51cm 1.44cm 1.49cm Bronchus Rt. 1.14cm 1.08cm 1.13cm Lt. 1.04cm 0.99cm 1.03cm In trachea, it showed about 0.7cm larger in male than female, and in bronchus 0.1cm larger on right than left. 6) Coefficiency between the haight of the lung and the angle of carina. Male Female Total Right 1.37 1.56 1.41 Left 1.53 1.74 1.58 Total 2.82 3.32 2.92 It shows 0.2 greater in female than male and 0.2 greater on left than right. 7) The above normal values are very important clinical value to evaluate early diagnosis, operability and prognosis of pulmonary and mediastinal tumorous condition. It is also good milestone to evaluate the status Korean adults.