To reveal the mechanism of collapsing gully erosion from a perspective of soil mechanic, the anisotropic characteristics of shear strength and the related influencing factors for undisturbed granitic soils from a typical granite weathered soil profile in southeastern Hubei were investigated by direct shear test. In accordance with the obtained results, the cohesion and internal friction angle of granite weathered soils ranged from 3.19 kPa to 19.26 kPa and 26.50° to 32.42° at saturation, and the maximum cohesion occurred for soils in the B₂ layer, while the difference of the internal friction angle along the investigated soil profile was less significant (p>0.05).In addition, cohesion and internal friction angle with significant anisotropy were larger in the horizontal direction than those in the vertical direction. Soil physicochemical properties that influencing of shear strength varied with profile direction. Specifically, the cohesion was mainly affected by capillary porosity (r=-0.97, p<0.01) and silt content (r=0.94, p<0.05) for soils in the vertical direction, and it was conditioned by silt content (r=0.91, p<0.05) for soils in the horizontal direction. However, the significant correlation between soil physicochemical properties and internal friction angle was solely observed for soils in the horizontal direction in which the variation of internal friction angle was influenced by liquid limit (r=-0.99, p<0.05). Furthermore, the anisotropy of shear strength of granitic weathered soils was mainly affected by natural water content (r=-0.98, p<0.01), organic matter (r=-0.93, p<0.05), and plastic limit (r=-0.97, p<0.05). These results would facilitate the understanding about the formation and development of collapsing gully erosion in southeastern China.