[Objective] The objective of this study was to explore the heterogeneity characteristics of the niche fissure soil in the Haifeng karst basin. The purpose was to provide scientific support for the control of Haifeng natural reserve soil erosion at the study area.[Methods] Through field sampling combined with a hydrometer method and aggregate wet sieve method, the soil mechanical composition, water-stable aggregates, and organic carbon of different niche fissures in the rocky desertification sloping land were analyzed.[Results] ① The surface niche and the underground fissure had a certain spatial correlation. Based on the niche type and fissure shape, the sampling fissures were initially classified as soil funnel, stone ditch fissure, and stone pit niche. ② Soil surface funnel, stone ditch fissure, and stone pit niche were heterogeneous because of such factors as fissure shape, niche type, and presence or absence of a root system. The content of sand particles in the stone pit niche was significantly higher than that of the soil surface funnel and stone ditch fissure (p<0.05), and the content of silt grains was significantly lower than that in the stone ditch fissure. The surface organic carbon content was significantly lower than that of the stone ditch fissure (p<0.05). The sand content of the funnel was significantly higher than that of the stone ditch fissure, the silt content was significantly lower than that of the stone ditch fissure, and the surface organic carbon content was significantly lower than that of the stone ditch fissure. ③ The soil stability of the soil surface funnel, stone ditch fissure, and stone pit niche gradually deteriorated with the increase of the soil layer depth, which was convenient for soil loss. Deep root vegetation intervened in the fissure soil system to improve the soil properties and enhance the resistance to soil erosion.[Conclusion] The nature of the niche fissure soil in the Haifeng karst basin is heterogeneous. The protection and utilization of the niche should be strengthened, and deep root vegetation should be planted to improve the physical and chemical properties of the soil and enhance soil erosion resistance.