Dissolved organic matter (DOM) is a labile carbon and nutrient pool inforest ecosystems and its properties are affected by plant species, soil properties, hydrological conditions and other factors. To investigate the effects of tree species on the composition and spectral properties of soil DOM leachate, one-year-old seedlings of Castanopsis carlesii (CC), Cunninghamia lanceolata (CL), and Ormosia Henryi (OP) were planted in the root boxes (0～60 cm), and no planting was set as the control. After a rainstorm in August 2021, soil DOM leachate in the root box was collected to determine its composition and spectral characteristics. The results show that: (1) The content of dissolved organic carbon (DOC) in soil leachate of Cunninghamia lanceolata seedlings was significantly higher than those of Ormosia Henryi and Castanopsis carlesii seedlings (p<0.05). (2) The value of the aromatic index (SUVA254) in the soil leachate of Castanopsis carlesii was the highest, and that of the hydrophobic index (SUVA260) in soil leachate of Cunninghamia lanceolata was the lowest. There was no significant difference in the molecular weight (SUVA280) in the soil leachate of different tree species. (3) There were no significant differences in the DOM fluorescence index (FluI), freshness index (Frl) and biogenic index (BIX) of soil leachate among the three tree species and no-tree species in the root box soil leachate. The DOM fluorescence humification index (HIX) of soil leachates in all treatments was less than one, and the HIX of soil DOM leachates of Ormosia Henryi and Castanopsis carlesii were significantly higher than that of no-tree control (p<0.05). Soil DOM leachate was mainly composed of three components, fulvic and humic acid-like (C1), humic acid-like (C2) and soluble microbial products (C3). Compared with the soil DOM leachates of Ormosia Henryi and Cunninghamia lanceolata, the proportions of C1 and C2 in the soil DOM leachate of Castanopsis carlesii was higher, while the proportion of C3 was low. (4) Pearson correlation analysis showed that DOC concentration was negatively correlated with UV index (SUVA254, SUVA260, SUVA280), two-dimensional fluorescence index FluI, and three-dimensional fluorescence component C2, while positively correlated with C3 (p<0.05). The results of this studyprovide some reference value for the study of soil biogeochemical cycles in the subtropical region.