The 213 first ribs Koreans were measured and morphologically studied. The results were as follows. 1. On average, the internal straight length of the first rib was 53.7㎜ (male), 49.9㎜ (female) ; the external straight length was 79.7㎜ (male),
75.4㎜ (female), the maximum straight length was 87.4㎜ (male), 81.2㎜ (female) ; the breadth was 15.2㎜ (male), 14.4㎜ (female) ; and the thickness was 5.5㎜ (male), 5.4㎜ (female). 2. The proportion of the scalene tubercle to the costal breadth was 0% to 90% (average 37%). 3. The incidence of the presence of the groove for the first thoracic nerve was 7.5%. 4. The common shapes of the articular surface of the head were ball-shape(41%), cylinder-shape (25%) and plane-shape (25%) ; and those of the tubercle were cylinder-shape (44%), saddle-shape (31%) and socket-shape (14%).