In order to examine the effects of the simulated nitrogen (N) and phosphorus (P) deposition on soil aggregate structure and nutrient content in alpine steppe, a short-term (<5 years) N and P addition experiment was set up in 2018 in Bayinbuluk Grassland Ecosystem Research Station relying on the Nutrient Network. There were four treatments in the experiment, including control treatment (CK), N addition, P addition, N and P interactive addition. The addition amount of N and P were 10 g m^-2 a^-1. In August 2021, plants and soil samples at 0-10 cm and 10-20 cm depth were sampled separately. Soil aggregates were classified using wet sieving method. The content of soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), available nitrogen (AN) and available phosphorus (AP) of bulk soil and aggregates with different particle sizes were analyzed. Our results revealed the following. (1) In Bayinbuluk alpine steppe, the proportion of water-stable soil aggregates from low to high was shown as following:0.053-0.25 mm, <0.053 mm, 0.25-2 mm, and >2 mm. The aggregates >2 mm was dominant, with the proportion ranging from 45.48% to 71.81%. (2) N addition significantly reduced the proportion of aggregates >2 mm and the mean weight diameter (MWD) of aggregates in the soil layer of 0-10 cm, while P addition reduced them in the soil layer of 10-20 cm. (3) The SOC content in soil aggregates in 0-10 cm soil layer was significantly higher than it in 10-20 cm soil layer. N addition significantly increased the AN content and N efficiency (Percentage of available N in total N) in aggregates in the 0-10 cm soil layer, but significantly decreased the AP content. P addition and NP interactive addition had no significant effect on aggregate nutrients overall. (4) The AN content of aggregates in the soil layer of 0-10 cm was positively correlated to aboveground biomass, while AN content and N efficiency of aggregates were negatively correlated to AP content and P efficiency (Percentage of available P in total P). In the soil layer of 10-20 cm, TP, AN and AP content of aggregates were positively correlated to N and P efficiency. In conclusion, N and P addition of 10 g m^-2 a^-1 decreased the stability of soil aggregates and affected different soil layers:N addition and P addition affected the stability of soil aggregates in 0-10 cm and 10-20 cm soil layers, respectively. N addition, which drove the redistribution of N and P in soil aggregates with different particle sizes, significantly increased and decreased the AN and AP content of soil aggregates respectively. P addition and NP interactive addition had no significant effect on aggregate nutrients overall.