Abstract: Forage grass is an important material basis and security guarantee for the development of livestock industry.Forage grass with high quality not only provides adequate nutrition for livestock, but also has important impact on the quality of livestock products.Alpine areas are not suitable for planting corn, alfalfa, and other conventional forage grass because of the insufficient accumulated temperature and transient frost-free season.However, the forage grass requirement of herbivorous livestock is large, for example, one sheep requires 657 kg hay per year, and it is very inelastic.In this case, shortage of forage grass has become a key limiting factor of herbivorous animal husbandry development and grassland ecological construction due to the dual pressures of the natural grassland degradation and the grazing blocked by fencing in alpine region.Plant factory is a new agricultural model which can achieve the purpose of efficient crop production by high-precision environmental control in facility.Though research and practice of plant factory in China have achieved the gratifying results in recent years, applying this technology to the forage grass production is still blank.For the energy-saving production of fresh forage grass in poor environment such as the alpine region, a container-type plant factory was designed and tested.To maximize space usage of the production departments, a six-level hydroponic cultivation system(1.5 m×0.55 m×2.3 m)(length×width×height) was installed.Semi-automatic control of artificial lighting lamps, automatic water circulation, and automatic heating facilities were used to optimize temperature, humidity, light, nutrient solution, and other environmental factors on forage grass production.In a plant factory, the optimal control for obtaining higher yield and better quality of plants was essential.Optimal regulators with temperature sensing probe and humidity sensing probe were used to control the water status and growth temperature of forage grass, and the nutrient solution was supplied by bottom watering.Light emitting diode (LED) fluorescent lamp was controlled by an automatic timing switch.All installation and debugging of facilities and equipments had been completed in a farming cooperatives of Tianzhu County, Gansu Province.Four batches of forage grass production experiments were carried out in January 2015 in order to test the operation and production capacity of equipment.The ordinary merchandise maize(Jinkai 3) bought from Jin Lvyuan Farming Technology Company was used as the experimental material.Maize after harvest was dried to a moisture content that was below 13% and then threshed for later use.The thousand kernel weight of experimental maize after the screening of impurities and broken grains was 330 g while the germination rate was higher than 85%.Temperature of the forage grass factory under natural conditions was between -21 and -4 ℃.According to the dimension of seedling tray used in this experiment(54 cm×27 cm×6 cm), we set up 5 treatments with different seed quantity of 300, 350, 400, 450 and 500 g) and each had 5 replicates.The upper and lower limit of the forage grass factory temperature were set to 30 and 26 ℃, respectively, and those of relative humidity were set to 85% and 65%, respectively.Supplementary illumination time was from 7:00 to 18:00.The effects of different planting densities on height, growth, root-shoot ratio and other indicators of forage grass were detected under the same conditions.And then the optimum seeding rate and productivity of the system were determined.The first batch of test material was sowed on January 5, 2015.Nine days after planting, the hydroponic forage grass with the seed quantity of 450 g showed the best production performance.The average height and yield were reached 24.96 cm and 1 891.5 g respectively, while the cost reduced to 0.4 yuan producing 1 kg fresh grass.On this calculation, this container-type plant factory could produce 16.33 ton fresh forage grass.Test results show that this factory production installation can meet the needs of pasture plant production in alpine region.