[Objective] The erodibility of topsoil on purple soil sloping farmlands in the Three Gorges reservoir area was investigated in order to provide a basis for spatial allocation design of soil conservation measures.[Methods] Two different kinds of purple soil sloping farmlands with soil bunds

horizontal ditch were selected

and topsoil was collected to determine the particle composition and organic matter content. Then the soil erodibility index was calculated by the environmental policy-integrated climate (EPIC) model

as to compare the particle composition

organic matter content and erodibility of the topsoil on purple soil sloping farmlands with different soil conservations.[Results] ① The content of silty particle in the topsoil of purple soil sloping farmlands was higher

and ranged from 45.78% to 76.29%

while the content of clay particle was relatively lower

ranged from 6.05% to 10.58%. At the slope scale

silty particle content at the lower slope of the upper field was significantly higher than that at the uphill position of the adjacent downhill plot

while sandy particle content was the opposite. At the field plot scale

sandy particle content was higher in the upper slope

and silty particle content and clay particle content were both higher in the middle and lower slope. ② The content of soil organic matter in topsoil on purple soil sloping farmlands ranged from 0.61% to 1.48%. At the slope scale

the organic matter content in topsoil of the lower slope of the upper field was significantly higher than that in the upper slope of the adjacent downhill plot. At the field plot scale

the organic matter content in the topsoil was mainly concentrated in the middle and lower slope. ③ The erodibility K value of topsoil on purple soil sloping farmlands was ranged from 0.043 8 to 0.059 2. At the slope scale

the erodibility K value at the upper slope of the lower slope of ridge and horizontal gully farmland was 16.55% and 6.30% lower than that at the lower slope of the adjacent upper field

respectively. At the field plot scale

the erodibility K value was higher in the middle and lower slope. The highest value occurred at the 3/4 of the slope. The erodibility K value of topsoil was positively related to silty particle content (p<0.01)

while negatively related to sandy particle content (p<0.01).[Conclusion] The anti-erosion capability of topsoil on purple soil sloping farmlands in the Three Gorges reservoir area is weak. Both soil bund and horizontal ditch have good soil conservation effects on purple soil sloping farmlands

which play an important role in improving the capability of soil anti-erosion.