Change patterns of dissolved organic carbon (DOC) along elevation gradients are important to elucidate responses of alpine cold soil carbon and its labile fractions to global change and soil warming. Repacked columns of homogenized alpine topsoil (0-20 cm) were incubated on-site at different altitudes (3 250, 3 438, 3 672, 3 852, and 4 098 m) along an altitudinal gradient. Incubated soil columns were sampled in September, November, March, May and July, respectively, and DOC contents in 0-10 cm and 10-20 cm in each column were respectively analyzed to determine seasonal variability in soil depth and altitude. The results showed that soil DOC was accumulated during the cold season and reached the peak in May, while decomposed in growth season; at the same sampling time, the contents of DOC tended to increase with altitude, soil DOC content at high-altitude zone was higher than at lower-altitude zones. Therefore, for subalpine soil, shrinkage of cold season induced by climate warming may extend the period of DOC depletion. Meanwhile, soil warming and contraction of freezing period could decrease the accumulations of soil DOC and enhance emissions of CO_2, indicating that alpine cold soil carbon pool would become a potential carbon source in the context of soil warming.