Abstract: Dissolved organic carbon(DOC) adsorption and its influence factor on the soil of Chinese fir plantation were s～udied with [M isotherm in laboratory experiments. The quantities of DOC adsorption in the lower soil are greater than that of the upper soil. There were remarkable linear relations between the quantity of DOC adsorption on soils and the initial DOC concentration in the solution before balanced, pH, concentrations of phosphorus, iron, and aluminum in solution affect the absorption of DOC obviously. There was highest DOC absorption at pH 5.0, and lowest at pH 7.0. Phosphorus in solution prevent the absorption of DOC, whereas Fe3+and A13+increase the DOC adsorption. The concentration of Fe3+in solution has greater influence on DOC absorption than that of aluminum. DOC affects the Fe3+, AP+dissolution greatly. The quantity and proportion of dissolved AP+are greater than that of Fe3+. The effects of DOC on Fe3+, AP+dissolution in lower soil are greater than that of upper soil.