Seasonal freeze-thaw regimes are the main factors influencing nitrogen (N) transformations in the temperate forests of northern China and are one of the key processes in the soil N cycle. However, the response to freeze-thaw cycles in different cenotypes is unclear. In this study, we conducted experiments to understand the effect of soil freeze-thawing on N transformations in soils (0-15 cm) from different cenotypes (woodland, grassland, and shrubs) in the forests of the Tianshan Mountains by simulating extreme soil freeze-thawing in different natural snow covers formed by canopy shading. The results showed that the content of ammonium nitrogen, NH₄⁺-N, and microbial biomass nitrogen (MBN) in the soil of the different cenotypes was positively correlated with soil temperature (at a depth of 5 cm), whereas the content of NH₄⁺-N in forest soil was lower than that in the other communities in the deep-freezing period. The content of nitrate nitrogen, NO₃^--N, was higher in forest soil than in the other community types. NO₃^--N was the major form of soil mineral N during the seasonal freeze-thaw period in the forests of the Tianshan Mountains; it accounted for 78.4% of soil mineral N. NO₃^--N content decreased by 64.6% from the early-thawing to late-thawing period in shrub soil, indicating a high risk of soil NO₃^--N loss. The N mineralization rate was significantly affected by the freeze-thaw period, and the cenotypes significantly influenced the ammonification rate. The main process involving soil N in the forests of the Tianshan Mountains during the freezing period was N immobilization. Investigating the response of soil N to freeze-thaw patterns in different communities would help us understand the soil N cycle in the northern forest regions.