Carbon (C) and nitrogen (N) are major constituents of plant and soil organic matter, and play a fundamental role in nutrient cycling, plant growth, and ecological function. Biogeochemical cycling of C and N has attracted much attention because of oxides released from ecosystems to the atmosphere are important factors driving global warming, and N availability limits plant productivity. Forests are the main C pool in terrestrial ecosystems and have a substantial influence on the global C cycle and atmosphere carbon dioxide (CO₂) concentrations. However, C and N storage in forests vary greatly because of differences in forest type, forest age, regional climate, and soil conditions. Forest harvest and restoration lead to different forest types and structures, which are important factors in decreasing and increasing C and N stocks. As such, research on C and N storage in each component of the forest ecosystems will be beneficial in the evaluation of the impact of different management regimes on C and N pools. The subalpine forest in western Sichuan is important for water resource conservation and is an ecological barrier in the upper reaches of the Yangtze River. Historically, large area of fir were cut down, and the area was restored with three different forest types (including plantation, natural secondary forest, forest under mixed influence of artificial and natural sources), which have different species composition, including the presence of spruce; the change in C and N stores is still unknown. More studies are needed to calculate C and N pools in this region because of its varying topography, community diversity, and complex ecosystems. In this study, C and N stores in different forest ecosystems of Abies faxoniana primary forest (AF), Picea asperata broadleaf mixed forest (PB), natural secondary forest (NS), and Picea asperata plantation forest (PA) in the subalpine of western Sichuan were quantified. The results showed that ecosystem organic carbon of AF, PB, NS, and PA was 611.18, 252.31, 363.07 tC/hm², and 239.06 tC/hm², whereas nitrogen storage was 16.44, 12.11, 15.48 tN/hm², and 8.92 tN/hm². Distribution patterns of carbon storage between soil and plants, not nitrogen storage, had changed between primary and restored forests. Carbon storage of primary and restored forests was dominated by vegetation and soil, respectively, whereas nitrogen storage was dominated by soil. Carbon storage of the tree layer accounted for 56.65%, 17.63%, 13.57%, and 22.05% of ecosystem total storage, soil layer (0-80 cm) occupied 32.03%, 69.87%, 76.20%, and 72.12% for carbon storage and 76.80%-92.58% for nitrogen storage. The proportion of carbon and nitrogen storage of woody debris and litter were 4.40-9.83% and 2.94-7.08%, respectively, which were higher than that of the understory vegetation. Abies faxoniana primary forest had high carbon storage, and it is especially important to protect. Three kinds of restored forests had high carbon sequestration potential, especially above-ground indicated by low above- and under-ground carbon storage rations. Natural secondary forest was beneficial to soil carbon accumulation and plantation forest to tree carbon storage.