When soybean sprouts aye grown in the closed condition (where the ratio of $ extrm{O}_2$ and $ extrm{CO}_2$ is 7 ： 3), amount of $ extrm{CO}_2$ is increased and $ extrm{O}_2$ is decreased with the passage of time. At the same time, the amount of ethylene is automatically increased. By increasing the concentration of ethylene gas up to 0.5-1.0 ppm in the growth room, the length of sprouts was restricted to 6-7 cm and the thickness of sprouts was increased to 2.70$pm$0.30 mm. The production of good quality sprouts which were fat and short was possible without application of any growth regulators such as indole-3-acetic acid known to have accumulation problem in humane body. To maintain the freshness during the transportation and prevent sprouts from rotting and bad smell at market, cold storage at 2-$5^{circ}$ and airtightness which will restrict photosynthesis and respiration (higher than $10^{circ}$) are needed. The freshness of sprouts is depended on the increase of $ extrm{CO}_2$ and the depletion of $ extrm{O}_2$ in the package. When the sprouts were stored below 1$0^{circ}C$ (preferably below 8$^{circ}C$), the concentration of $ extrm{CO}_2$ in the package remained below 30% for more than 60 hours, which was possible to keep sprouts in freshness without any offensive odor, But sprouts were maintained at $13^{circ}$ for more than 25 hours, the concentration of $ extrm{CO}_2$ increased over 30% and produced an offensive odor. The little amount of $ extrm{O}_2$ gas was existing for 30 hours at $5^{circ}$ but it was disappeared completely within 7 hours over $10^{circ}$ and the sprouts became rot and produced severe offensive odor.