Abstract: To determine the types and amounts of fatty acids in silages produced from vegetation on the Hulunbeir Meadow Steppe, 40 wild forages were ensiled and their fatty acids contents were analyzed by gas chromatography after 45 days. The main fatty acids in the 40 forage silages were six long-chain fatty acids, especially palmitic acid and linolenic acid. The linoleic acid contents ranged from 0.1735% to 40.2036%. The ether extract and total fatty acids contents of the 40 silages ranged from 1.3507% to 10.8523% and from 0.0376% to 3.2505%, respectively, and the saturated fatty acid and unsaturated fatty acid contents ranged from 0.0252% to 1.5333% and from 0.0515% to 1.7172%, respectively. There was no obvious correlation between ether extract contents and the contents of the six main fatty acids, while there were complex correlations among the different fatty acids. There were pronounced differences in fatty acids composition and proportions among the 40 different forages, and the nutritive values of fatty acids of forages also differed depending on the genera and families of the vegetation.