The methane emission from ruminants was an important source of greenhouse gases, which makes ruminant farming had a broad and far-reaching impact to climate change, and it has become a major concern of environmental decision- making factor. Studies showed that dietary nitrates with safety dose not only can become the main source of nitrogen silage for animal protein synthesis, but also have the long-term function of curbing greenhouse gas emissions. Achievements of researches on application of nitrate on ruminant at domestic and abroad were reviewed in the paper. This will provide references to better application of nitrate in ruminant production.