Abstract: Under the conditions of dry arable land, two forage species were selected as planting materials,which were Aohan Medicago sativa （Leguminous） and Elymus sibiricus （Gramineous）, respectively. The eftects of three classical planting patterns, including monoculture of Medicago sativa, monocuhure of Elymus sibiricus and mixed sowing of Elymus sibiricus and Medicago sativa （E：M=2：I）, on the plant characteristics and economic benefits were discussied. Detials were given for plant height, dry weight of stem, dry weight of leaves, total dry weight of aboveground, and total production during each growing season. The resuhs showed that as the defoliation fi＇equency was twice in the first sowing year, the plant height, stem-leaf ratio and dry weight of stem of Elymus sibiricus increased by 8.93%, 63.55% and 13.25%, respectively under the mixed sowing planting pattern compared with the monocuhure planting pattern. Meanwhile, dry weight of leaves and plant weight decreased by 48.28% and 1.35%, respectively. The significant difterences of all the above characteristics were at P〈0.05 level. The dry weight of stem increased by 13.25%, the dry weight of leaves decreased by 48.28%, and the dry weight of plants decreased by 1.35%. In addition, the plant height, stem-leaf ratio, dry weight of leaves and dry weight of stem of Aohan Medicago sativa decreased by 27.49%, 10.91%, 7.02% and 3.28% under the mixed sowing planting pattern, repeetively, while plant dry weight increased by 1.04%. The significant ditterenees of all the above characteristics were at P〈0.05 level. Furthermore, Aohan Medicago sativa represented the highest total production with 5 720.83 kg/hm^2,whieh was significantly greater, by 16.46%, than that of mixed torage （/）〈0.05） and highly significantly greater, by 87.98%, than that of monoeuhure Elymus sibiricus （P〈0.01）. Aohan Medicago sativa represented the highest benefit value with 6 255.58 yuan/hm^2, which was highly significant greater by 52.22% and 559.66% than that of mixed forage （P〈0.01） or monoeulture Elynms sibirieus （P〈0.01）, respectively.

Key words: Planting pattern;Medicago sativa;Elymus sibiricus;Dry matter;Economic benefit