Abstract:[Objective]The influences of slope inclination aspect on hydrological characteristics in the soil surface layer and on the greening steep slopes were studied in order to provide a basis for the effective use of water resources in the process of vegetation restoration on steep loess slopes. [Methods] We conducted a comprehensive study on two steep slopes with inclinations of 46°~55° and 56°~65° located in arid and semi-arid regions. These slopes were categorized into four slope orientations: shady slopes, semi-shady slopes, sunny slopes, and semi-sunny slopes. Arboriculture and shrubbery greening initiatives were implemented on these steep slopes over an 8-year period. We conducted extensive analyses on basic soil properties, water-holding capacity, and infiltration of the 0—40 cm soil layer. Furthermore, we explored the intricate relationship between various soil factors and terrain factors. [Results] ① The interaction between slope classes and slope orientations stand factors had a significant effect (p<0.05) on soil bulk weight, mass water content, total porosity, and maximum water holding capacity in the 0—40 cm soil layer, and a significant effect (p<0.05) on soil gross tubular porosity and gross tubular water holding capacity in the 0—20 cm soil layer, However, these differences were not statistically significant (p>0.05) under alternative conditions. ② Maximum water-holding capacity was found to be higher for the 46°~55° steep slopes than for the 56°~65° steep slopes. Conversely, the average infiltration rate was higher for the 56°~65° steep slopes than for the 46°~55° steep slopes. Sunny slopes had the highest maximum water-holding capacity (522.42 t/hm2), followed by semi-sunny slopes (505.03 t/hm2), shady slopes (502.27 t/hm2), and semi-shady slopes (496.15 t/hm2). Similarly, the average soil infiltration rate was highest for sunny slopes (0.79 mm/min), followed by semi-sunny slopes (0.59 mm/min), shady slopes (0.42 mm/min), and semi-shady slopes (0.30 mm/min). ③ A two-factor analysis of variance revealed that the interaction between slope class and slope aspect had the most significant impact on the hydrological characteristics of steep slopes. [Conclusion] Basic soil properties were better for 46°~55° steep slopes than for 56°~65° steep slopes. Moreover, sunny and semi-sunny slope orientations exhibited greater water-holding capacities than shady and semi-shady slope orientations.