Distribution characteristics of soil organic carbon (SOC) and total nitrogen, as well as the coupling relation between SOC and TN are important areas for research in the carbon and nitrogen cycling in mountain ecosystem. In this study, vertical transects in Abies faxoniana forests at altitudes between 2920 m to 3700 m in Wolong were investigated to determine the distribution of soil organic carbon (SOC), soil total nitrogen (TN), and labile soil organic carbon fractions (LFOC) along the altitudinal gradient, as well as the coupling relationships among them. The results showed that: i) SOC content in the humus layer increased along the altitudinal gradient and had a negative relationship with temperature. LFOC and particle state organic carbon (POC) increased followed by a decrease along the altitudinal gradient. TN did not significantly change with increasing altitude, whereas LOFC, POC, and TN significantly increased near the forest line. TN and SOC in the 0-10 cm depth layer were double-peaked as altitude increased, with peaks at 3089 m and 3260 m, respectively. ii) The major fraction of LFOC and ROC were observed in the humus layer and the 0-10 cm depth layer of soil. In addition, LFOC/SOC and POC/SOC in the humus layer increased along the altitudinal gradient, whereas LFOC/SOC and POC/SOC decreased in the 0-10 cm layer of soil along the altitudinal gradient, indicating the stability of SOC in the humus layer decreased along the gradient, whereas the stability of SOC in the 0-10 cm soil layer increased as altitude increased. iii) SOC was significantly and positively correlated with TN, and SOC content was the main factor affecting the TN. However, TN did not exhibit a significant relationship with the labile fractions of SOC in the humus layer. iv) The ratio of C/N in soil and that in microbial biomass were higher than 25 at an elevation of 3177 m, which was the main factor causing the significant decrease in the SOC content.