A comparative analysis of soil physical properties and their influencing factors was carried out between soils developed from either acidic and calcareous rocks in Xiaoshengtang small watershed in the Yimeng mountainous region. The results showed that:(1) The soils developed from acidic rocks contained more gravel and sand than those from calcareous rocks. Soil textures ranged from sandy loam to loamy sand, and the gravel content increased with soil depth. The silt and clay contents of the soils were slightly higher in soils developed from calcareous rocks than from acidic rocks. However, the particle size compositions of the upper and lower soil layers were similar for soils from the calcareous rocks. Both soil types had relatively low fractal dimensions, which were influenced by the parent rock, but those of the soils developed from acidic rock were lower. Furthermore, they were both poorly developed soils with gravel contents higher than 10%.(2) Soils developed from acidic rock had higher bulk densities than that from calcareous rocks, which had higher total and capillary porosities. The bulk densities and capillary porosities of the two soils increased with increasing soil depth and, conversely, the total porosities and non-capillary porosities decreased. Furthermore, the capillary porosities were mainly influenced by soil fractal dimensions.(3) The saturated hydraulic conductivities of the soils developed from acidic rock were higher than those from calcareous rock, and they were higher in the 10-20 cm soil layer than in the 0-10 cm layer. However, the saturated hydraulic conductivities of the soils developed from calcareous rock did not exhibit consistent changes in different soil layers. Soil texture, especially the sand and silt contents, was the main influencing factor of soil saturated hydraulic conductivity in the Yimeng mountainous region.