Abstract: Soil acid phosphatase activity is a critical indicator of soil phosphorus bioavailability. To investigate the impact of different tree species on soil acid phosphatase activity and provide theoretical support for afforestation in subtropical regions. This study selected 12 common tree species in subtropical regions, measured six functional traits for each species, including both above-ground and below-ground traits, as well as determined the soil acid phosphatase activity in each sample plot, and evaluated the relationship between the functional traits of the 12 tree species and soil phosphatase. The results showed that: The specific leaf area of the 12 tree species ranged from 5.6 to 9.4 m²·kg⁻¹; leaf dry matter content varied from 287.73 to 486.39 mg·g⁻¹; leaf nitrogen content ranged from 1.1% to 2.01%; leaf phosphorus content ranged from 0.04% to 0.13%; root diameter varied from 0.41 to 0.73 mm; and specific root length ranged from 19.89 to 57.14 mm. Soil acid phosphatase activity exhibited a range from 42.3 to 212.0 μmol·g⁻¹·h⁻¹, with the highest values recorded in Myrica cerifera（212.0 ± 46.9 μmol·g⁻¹·h⁻¹）and the lowest in Quercus variabilis（42.3 ± 8.4 μmol·g⁻¹·h⁻¹）. The Pearson correlation analysis between the functional traits of 12 tree species and soil acid phosphatase activity shows that the specific leaf area and root diameter of different tree species are positively correlated with soil acid phosphatase activity, while leaf dry matter content and specific root length are negatively correlated with soil acid phosphatase activity. The results of the study suggest that the functional traits of different tree species can influence soil acid phosphatase activity by affecting the plant’s phosphorus acquisition strategy.