Soil soluble carbon is the most active part of soil organic carbon pool,which is often used as a sensitive indicator for the initial change of soil carbon turnover,but its content is jointly regulated by plant litter input,forest type,and seasonal variation of water and heat.The monthly dynamics of soil dissolved organic carbon (DOC) and hot water-soluble carbon (HWSC) contents and their responses to litter input during the growing season were analyzed by carrying out a field situ incubation experiment of two plantations (Castanopsis carlesii and Cunninghamia lanceolata/Chinese fir) in subtropical China.The results showed that litter input,forest type and monthly climate significantly affected the content of soil soluble carbon components (p＜0.001).Soil DOC and HWSC contents in Chinese fir plantation were higher than those of Castanopsis carlesii plantation by 15.09% and 13.06%,respectively,but the degree of aromatation of soil soluble organic matter was higher in Castanopsis carlesii plantation.After one growing season of incubation,soil DOC and HWSC contents increased significantly in both plantations.Litter increased soil DOC and HWSC contents in Castanopsis carlesii plantation during the growing season,but which in Chinese fir plantation displayed seasonal difference.These results indicated that soil DOC and HWSC contents were higher in Chinese fir plantation than Castanopsis carlesii plantation,but litter could promoted the DOC and HWSC contents of Castanopsis carlesii plantation,which would be easy to be lost during leaching.