The methane (CH₄) fluxes in grasslands are sensitive to changes in precipitation and soil nitrogen concentrations, which was poorly understood, especially on the Tibetan Plateau. Therefore, an experiment was conducted from May 2012 to October 2013, by using the static chamber technique and gas chromatography method. We set up five treatments: an increased 2 g m^-2 NH₄NO₃ treatment (2gN); an increased 4 g m^-2 NH₄NO₃ treatment (4gN); and treatment with precipitation increased by 20% (Pre), and added 2 g m^-2 NH₄NO₃ and precipitation (20%) treatment (N+Pre), and a control treatment (CK). The five treatments showed decreasing CH₄ uptake rates in the following order: CK (71.66 ± 6.6 µg m^-2 h^-1) > N+Pre (58.57 ± 3.7 µg m^-2 h^-1) > Pre (52.66 ± 2.3 µg m^-2 h^-1) > 2gN (47.63 ± 3.1 µg m^-2 h^-1) > 4gN (39.12 ± 3.3 µg m^-2 h^-1). The 2gN and 4gN treatment resulted in 33.5% and 45.4% lower CH₄ uptake than the CK treatment, respectively. The path analysis indicated that the above-ground biomass and litter fall were the most important factor promoting and limiting the CH₄ uptake rate of alpine meadow, respectively.