This experiment was carried out to investigate the effect of growth stags on the change of weight and percent of leaf, stem, root and grain in Coix Iacryma L. and their chemical composition. The result. obtained were as follows. 1 . The grass height, leaf length and leaf width of Coix Iacryma L. on the green basis were 224㎝, 58㎝ and 4㎝, respectively. It was found that Coix Iacryma L. was nearly finished to gores by the 25th of July. 2. The ratio of leaf and stem per each Coix Iacryma L. on the green basis was progressively decreased and increased, respectively as the growth stage elapsed. However, the ratio of root per each Coix Iacryma L. was almost constant as the growth stage passed away. On the other hand, in the dried basis the ratio of leaf and root per each Coix Iacryma L. was progressively decreased as the growth stage elapsed. The ratio of stem and grain per each Coix Iacryma L. was progressively increased as the growth stage elapsed. 3. The dry matter content of Coix Iacryma L. was 32% at the beginning of October and among this content, the ratio of leaf was greatly decreased and the ratio of stem and grain was progressively increased as the growth stage passed away. 4. Crude protein content of leaf of Coix Iacryma L. by the growth stage on the dried basis was 20% in June and 11% in October and decreased as the growth stage increased. Crude fiber content of leaf of Coix Iacryma L. by the growth stage on the dried basis was 20% in June and 32% in October and increased as the growth stage passed away. On the other hand, content of crude protein and crude fiber of stem and root has the same tendency as leaf has. In the green basis, crude protein content of leaf of Coix Iacryma L. was 2 to 3% and crude fiber content of leaf of Coix Iacryma L. was 3 to 8%. 5. Content of crude protein and crude fiber of grain of Coix Iacryma L. on the dried basis was 12 to 14% and 16 to 29%, respectively and decreased slightly as the growth stage increased. In the green basis, content of crude protein and crude fiber was 2 to 9% and 4 to 14%, respectively and increased slightly as the growth stage elapsed.