Abstract: The alfalfa in the suburb of Beijing was investigated. The results showed that soil moisture in alfalfa grassland before winter can be compensated by the precipitation in summer-autumn. The upper layer, limited natural rainfall should be stored up into the soil timely to improve the water use efficiency. By comparison with one yearly yield of ten varieties of alfalfa, Medicago sativa L.“Zhong mu NO1”and Medicago sativa L.“Gen xuan” were proved to be the more excellent breeds, whose yields are also higher. So the two breeds are worth to be popularized for planting in the suburb of Beijing.