Four types of upland forest soils derived from various parent materials in hilly region of east-ern Hunan were sampled vertically to parent material/rock horizon to investigate their content and stor-age of soil organic carbon ( SOC) and dissolved organic carbon ( DOC) , the proportion of DOC to SOC ( DOC/SOC) and whole-profile ultraviolet-visible ( UV-Vis) spectroscopic features of DOC , in order to evaluate DOC quantity and quality and their controls in deep soil horizons .Results showed that the content of DOC ranged from 2.33 mg? kg -1 to 185.26 mg? kg -1 , first decreased and then increas...