Abstract: To select alfalfa varieties which could grow well in Northern Xinjiang, 4 American‘WL’alfalfa varieties including‘WL168HQ’,‘WL343HQ’,‘WL363HQ’and‘WL354HQ’were introduced to plain area of northern Xinjiang. Growth period, yield and main nutritional components of the 4 varieties were analyzed in 2 years. The results showed that growth period of the 4 varieties had no obvious difference, and the wintering survival rates were above 95%. The 4 alfalfa varieties showed very good adaptability to the local environment. The crude protein contents of‘WL’varieties were higher than that of‘Daye’. Crude protein and NDF content of‘WL168HQ’in blooming period was 20.32% and 35%, respectively. In the second year, the total yield of ‘WL168HQ’and WL343HQ’were up to 24024.7 and 23590.7 kg/hm2 respectively, increased by 25.2% and 23.8% compared with that of‘Daye’(P<0.01). The results indicated that‘WL168HQ’and‘WL343HQ’had strong adaptability, high yield and rich nutrition in northern Xinjiang. Thus, we suggested that these varieties should be widely cultivated in areas with similar environment, and also be used as breeding material of possible new alfalfa varieties.