The tree fine root (<2 mm in diameter) system is a functionally highly important compartment of forest ecosystems. Fine root traits are a result of long-term adaptation of trees to local habitat, and they strongly reflect the information of environmental changes. The objective of this study was to investigate differences in fine-root traits between two subtropical tree species, i.e., the early-succession species, Pinus massoniana (PM), and the late-succession species, Castanopsis carlesii (MZ) in their respective monoculture plantations in Sanming City, Fujian Province. Three 20m×20m plots were established in each forest type. Fine roots were extracted using soil core method and measured for their biomass, vertical distribution, and morphological and branching structure. The extinction coefficient (β) from the model of vertical root distribution: Y = 1 - β^d was used to represent root distribution. The results showed that root biomass density (RBD), root surface area density (RSD), and root length density (RLD) decreased with the increasing soil depth. Their levels in the 0-80 cm soil layer of the MZ stand were (0.21±0.06) kg/m³ (RBD), (3.15±1.25) m²/m³ (RSD), and (2202.84 ±517.03) m/m³ (RLD), which were 1.6, 1.2, and 2.2 times higher than those in the PM stand, respectively. Soil depth had a significant effect on RBD, RSD, and RLD in both stands. Root extinction coefficients (β) for root biomass, root surface area, and root length were each higher in the PM stand than in the MZ stand, indicating that fine roots in the PM stand were distributed more evenly along the soil profile, while those in the MZ stand were concentrated primarily in the surface layer. The average root diameter (RD) and specific root surface area (SRA) in the PM stand were (0.86±0.04) mm and (191±32) cm²/g, respectively, which were 1.4 and 1.3 times larger than those in the MZ stand, respectively. Specific root length (SRL) and root tissue density (RTD) in the MZ stand were (10.73±0.46) m/g and (0.49±0.06) g/cm³, respectively, which were 1.4 and 2.0 times higher than in the PM stand. Soil depth had significant effects on RD, RTD and SRA and little effect on SRL in the MZ stand, whereas none of these variables were significantly affected by soil depth in the PM stand. RD and RTD differed significantly between these two stands in all soil depths. Except for the 0–10 cm soil layer, there was no significant difference between two stands at all depths in terms of SRA and SRL. Fine roots with coarser diameter and lower tissue density in the PM stand can grow rapidly to fill the soil space, adapting to the arid soil, whereas those with thinner diameter as well as higher SRL and RTD in the MZ stand enable them to strongly compete for nutrients while avoiding herbivory. Specific root tip density (SRT) and specific root forks density (SRF) of fine roots in the MZ stand were (4288.44±63.35) ind./g and (1164.35±155.38) ind./g, respectively, which were both 2.2 times those in the PM stand. Soil depth exerted significant effect only on SRT in the MZ stand. Roots with higher branching intensity in the MZ stand can rapidly exploit nutrient-rich soil patches. We conclude that there are contrasting fine-root traits in tree species at different succession stages, probably reflecting the differences in soil foraging strategy.