[Objective] Purple soil sloping farmland is an important cultivated land resource in the upper reaches of the Yangtze River. Therefore, clarifying the change characteristics and main obstacle factors influencing purple soil sloping farmland under different erosion degrees is important.[Method] In a cultivated layer of sloping farmland, five erosion degrees (0, 5, 10, 15, 20 cm) were set up in situ. The cultivated layer quality index (CLQI) and obstacle degree (M_ij) were calculated by selecting 10 quality indexes, including bulk density, total porosity, saturated hydraulic conductivity, soil compactness, soil shear strength, organic matter, total nitrogen, total phosphorus, pH and cation exchange capacity. Thus, the change characteristics of cultivated layer quality and obstacle degree under different erosion degrees were quantitatively evaluated.[Result] Soil erosion destroyed the structure of the cultivated layer, resulting in deterioration of cultivated layer quality index. Total porosity, saturated hydraulic conductivity, shear strength, cation exchange capacity, total nitrogen and total phosphorus decreased with the increase of erosion degree, while bulk density and soil compaction increased with the increase of erosion degree. The order of obstacle degree from cultivated layer quality was soil compaction (17.04%) > saturated hydraulic conductivity (15.83%) > total nitrogen (11.49%) > organic matter (11.47%) > total phosphorus (10.73%). The main obstacle factors of cultivated layer quality were soil compaction, saturated hydraulic conductivity, total nitrogen, organic matter and total phosphorus. The effect of soil erosion and management measures on soil compaction was significant (P < 0.01) while the effect of management measures on organic matter and saturated hydraulic conductivity was extremely significant (P < 0.01). Also, the interaction between soil erosion and management measures had a significant (P < 0.05) effect on saturated hydraulic conductivity and organic matter.[Conclusion] The main obstacles of cultivated layer types of purple soil sloping farmland can be divided into soil nutrient-poor obstacle and soil acidification obstacle. All the findings above can provide a theoretical basis for quality control of purple soil sloping farmland.