Dissolved organic matter (DOM) is a crucial component of soil organic matter and is attracting more attention. It plays an important role in global C/N cycling, and mediates many soil processes. As a small but active organic matter pool, the structural and chemical characteristics of DOM have recently been considered to be sensitive indicators of soil fertility. In many areas of southern China in the 1960's, many natural broad-leafed forests were transformed into productive plantations, in which soil fertility recovery is now of great concern in the context of global climate change. However, little is known about how these conversions have affected the quantity and quality of soil DOM.In contrast to conventional methods, spectroscopic methods can provide a lot of useful information on the structural characteristics of DOM. Therefore, in this study we investigated the quantity and quality of soil DOM in a natural forest of Castanopsis kawakamii (NF) and three adjacent plantations of Schima superba (SCS), Castanea henryi (CAH), and Fokienia hodginsii (FOH) in Sanming Fujian province in subtropical China. We evaluated dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) concentrations,special ultraviolet-visible absorption (SUVA), humification index by emission fluorescence spectrum (HIX_(em)),humification index by synchronous fluorescence spectrum (HIX_(syn)),fluorescence efficiency (F_(eff)),and Fourier transformed infrared (FTIR). In the 0-5 cm soil layer, soil DOC concentrations decreased significantly (P < 0.05) after NF was transformed into SCS, CAH, and FOH, the relative proportions were 66.1%, 69.9%, and 29.4% respectively. The concentration of soil DON also decreased; in the 5-10 cm layer, concentrations of soil DOC and DON in all plantation types except FOH were lower than those in NF. Concentrations of soil DOC and DON in the 0-5 cm layer were higher than those in the 5-10 cm in all cases. Aromaticity and humification indices (HIX_(em),HIX_(syn)) of soil DOM in NF were significantly (P < 0.05) higher than those of plantations, and they all decreased with depth. Feff of soil DOM increased after forest conversion. The fluorescence spectrum showed that the relative absorption intensities of aromatic-aliphatic and ligninderived fluorophores in soil DOM in NF were stronger than that of plantations. FTIR spectra of soil DOM from all forests featured -OH,aromatic C =C,-COO~-,C-O carbohydrates,but with varying relative intensities. Higher abundances of carbohydrate rendered soil DOM in plantations less complex. In comparison with plantations,soil DOM in natural forests was nutrient richer and contained more complex and highly condensed compounds. Therefore, it was better for the accumulation of organic matter because molecules with more complex structures were more likely to be absorbed onto the soil surface instead of being leached out of the ecosystem. The differences in soil DOM between natural forests and plantations might be attributed to changed litter input,forest management practices, and human activity, and FOH is the most suitable plantation type for soil fertility recovery.