By the use of three-dimensional excitation emission matrix fluorescence coupled with parallel factor analysis (EEM-PARAFAC) and fluorescence regional integration (FRI) analysis, DOM characteristics of the alpine soil and its changing tendency along an altitudinal gradient from 3200 to 4000m in the western Sichuan province were studied. The results showed that, the DOC concentrations for the alpine soil ranged from 0.47 to 0.81g/kg, showing an increasing trend with the altitude elevation in the same soil layer, and mostly higher DOCs in the topsoil layer than the subsoil. There were always five DOM components in the tested soils, namely, aromatic protein substance I (tyrosine, Peak I), aromatic protein substance II (BOD₅, Peak II), fulvic acid-like (Peak III), soluble microbial byproduct-like (tryptophan, Peak IV) and humic acid-like (Peak V). The fulvic acid-like and humic acid-like species are two major DOM components for the alpine soil. FRI values decreased with the altitude increase. Values of fluorescence characteristic parameters (fluorescence index FI, spontaneous source index BIX, humification index HIX, freshness index β:α) have indicated that, the stability of soil DOM decreases with altitude elevation, while the bioavailability increases with elevation. Therefore, climate warming may lead to increased DOM decomposition and decreased contents in high altitude soils but with an increased stability.