[Objective] The relationship between the fractal characteristics of soil particle size distribution and properties in different forest types in the typical karst regions of Guangxi Zhuang Autonomous Region (GZAR) was investigated in order to provide scientific guidance for sustainable forestry development in rocky desertification areas. [Methods] The particle size distribution and properties of soil in Eucalyptus spp., Pinus massoniana, and natural secondary forests were determined. Single and multiple fractal dimensions of soil from different forest types were calculated using fractal models, and the their correlations with soil properties were explored. [Results] Compared to natural secondary forests, the bulk densities of Eucalyptus spp. and P. massoniana plantations were 23% and 15% lesser, respectively. However, the total porosities of Eucalyptus spp. and P. massoniana plantations were greater by 27% and 17%, respectively, than that of natural secondary forests. The clay contents in Eucalyptus spp. and P. massoniana plantations were lower(58% and 42%, respectively) whereas the sand contents were higher (24% and 14%, respectively), than that of natural secondary forests. Additionally, the single fractal dimensions (D_s) were 6% and 4% lesser in Eucalyptus spp. and P. massoniana plantations, respectively, than that of secondary natural forests. Furthermore, the available phosphorus, readily available potassium, and total calcium contents for Eucalyptus spp. were 68%, 49%, and 6% lower, and, those for P. massoniana were 42%, 40%, and 25% lower, respectively, than those of secondary natural forests. D₀-D₂, ΔD and Δα were the multifractal parameters that reflect the heterogeneity of soil particle size distribution across different dimensions; for Eucalyptus spp. (0.13, 1.29, 1.52) and P. massoniana (0.13, 0.99, 1.18) plantations these values were higher than those for natural forests (0.08, 0.83, 1.02). Furthermore, there was a significant correlation between multifractal parameters and soil nutrient content in the different plantations. [Conclusion] Improper cultivation and management of plantations in karst regions may promote the loss of fine soil particles and depletion of key nutrients. This, in turn, can result in a concentration of the soil particle size distribution in low-probability dense areas, increasing the heterogeneity of the soil particle size distribution and further accelerating the process of rocky desertification. The single fractal dimension D_s can reflect the degree of soil fertility degradation in karst forest areas, and the multifractal parameters can reveal the heterogeneous distribution characteristics of soil particle size at the microlevel in detail. Therefore, single and multiple fractal dimensions have the potential to become precise indicators for evaluating the soil quality of plantations in karst regions.