The variation of the esterase isozyme, germination rate, chemical composition and digestibility of field bean(G1ycine soja S. and Z.) were estimated. The results are as follows; 1. The banding patterns of the esterase isozyme in field bean were varied with the tissue and habitat. 2. The enzyme activity of the Est-I, Est-2, Est-3 and Est-4 in field bean showed a high value compared with the other enzyme. 3. The range of germination temperature in field bean was 10-40C and the optimum germination temperature was 25- 38^{circ}C.$. 4. The crude protein(CP) contents was 19.9% in the whole plant, 27.8% in the leaf and 45.9% in the seed, the cellulose contents was 29.5% in the whole plant, 23.0% in the leaf and 13.8% in the seed, the neutral detergent fiber(NDF) was 62.6% in the whole plant, 47.9% in the leaf and 47.9% in the seed and the acid detergent fiber(ADF) was 44.5% in the whole plant, 28.4% in the leaf and 28.4% in the seed, respectively. 5. The digestibility of the field bean was 44.1% in the whole plant, 49.6% in the leaf and 75.1% in the seed, NDF was 26.2% in the whole plant 46.2% in the leaf, ADF was 29.0% in the whole plant, 47.7% in the leaf and 58.0% in the seed and Cellulose was 48.7% in the whole plant, 58.0% in the leaf and 70.2% in the seed, respectively. 6. Total digestible nutrients(TDN) of the field bean was 47.4% in the whole plant, 51.5% in the leaf and 70.2% in the seed, respectively. The digestible energy(DE) value was 2.1 kcal/g in the whole plant, 2.27 kcal/g in the leaf and 3.10 kcal/g in the seed and the metabolizable energy(ME) value was 1.72 kcal/g in the whole plant, 1.86 kcal/g in the leaf and 3.23 kcal/g in the seed, respectively.