Determination of several normal values were carried out in healthy 1805 cases of Korean adults, 1436 cases ofmale and 369 cases of female, by the drawing and calculation on chest roentgenogram. In many instances, the changenormal values provides an important clinical values, and often is decisive to evaluate the diagnosis, treatmentand prognosis of pulmonary , cardiac and mediastinal disease. The results are as follows; 1) Height of both lungfields; Male Female Total right 22.1cm 19.9cm 21.6cm left 23.7cm 21.2cm 23.2cm It shows about 2.0cm larger in malethan female and about 1.6cm larger on left side than right. 2) Transverse diameter of thoracic cage and heart, andcoefficiency between above two values. (C/T ratio) Male Female Total Thoracic cage 29.9cm 27.7cm 29.4cm Heart12.7cm 12.6cm 12.7cm C/T 0.43 0.44 0.43 Thoracic cage reveals 2.0cm larger in male than female. 3) Thoracicvertebral 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 comon level of bifurcation in T-5, and next T-6 in both sex. 4) The angle of carina. Male Female Total Rightbronchus 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 largerin left side than right. 5) Transverse diameter of trachea and bronchus. Male Femal Total Trachea Bronchus 1.51cm1.44cm 1.49cm Rt. 1.14cm 1.08cm 1.13cm Lt. 1.04cm 0.99cm 1.03cm In trachea, it showed about 0.7cm larger in malethan female, and in bronchus 0.1cm larger on right than left. 6) Coefficiency between the haight of the lung andthe 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 0.2greater in female than male and 0.2 greater on left than right. 7) The above normal values are very importantclinical value to evaluate early diagnosis, operability and prognosis of pulmonary and mediastinal tumorouscondition. It is also good milestone to evaluate the status of Korean adults.