With rapid increase of global atmospheric nitrogen deposition, the nitrogen-limited subalpine forest ecosystem in western China maybe significantly affected. Soil microorganisms are important component part of the ecosystem and they are essential participants in the matter circulation and energy flow. Due to different background of ecosystem types, soil nutrients, and nitrogen deposition values, there are many uncertainties of soil respiration and soil microbial biomass carbon and nitrogen (MBC and MBN)in response to nitrogen application. Will nitrogen application promote the immobilization of soil carbon and nitrogen by soil respiration and microbial biomass in the subalpine forest ecosystem?Based on this assumption, a 60-year-old Larix mastersiana of subalpine coniferous forest in western Sichuan was taken as the research object.Dynamic of soil respiration and soil microbial biomass carbon and nitrogen were measured under four levels of nitrogen application control tests(CK:0g m^-2a^-1, N₁:2g m^-2a^-1, N₂:5g m^-2a^-1, N₃:10g m^-2a^-1)during a growing season (April-October).The results showed that nitrogen application had significant effects on soil respiration and soil microbial carbon and nitrogen, which significantly promote these indicators. Soil respiration flux increased by 11%-15%, soil microbial biomass carbon increased by 5%-9%, and soil microbial biomass nitrogen increased by 23%-34%. The promotion of soil respiration is most facilitatedunder the level of nitrogen (5g m^-2a^-1).Correlation analysis found that soil respiration had significant positive correlation with MBC, MBN and microbial metabolic quotient, and MBC and MBN had significant positive correlation with soil temperature and negative correlation with soil humidity.General linear regression analysis found soil respiration rate had significant positive correlation with soil temperature and negative correlation with soil moisture (P < 0.001),Soil temperature sensitivity coefficient Q₁₀value (7.10) was significantly higher than the control Q₁₀value (4.26).