The main purpose of this study is to establish the transverse hilar measurements in normal Korean adults. The authors have been feeling that the transverse hilar measurements in normal Korean adults would be significantly different from those of American. The transverse hilar measurements in normal Korean adults were established, and they were compared with those given by foreign authors in an attempt to bring out salient difference in measurements. The authors performed measurements in healthy Korean(over 40 years of age), which included 100 adults of either sexes. Following results were obtained : 1) The right hilar measurement is 4.5±0.36 cm and the left 5.6±0.48 with the total transverse diameter being 10.1±0.80 in male adult. 2) The right hilar measurement is 4.0±0.39 cm and the left 5.1±0.43 with the total transverse diameter being 9.1±0.72 in female adult. 3) There were significant difference in the total transverse hilar distance between Korean and American.