[Objective] The dynamic changes in soil moisture and its response to rainfall in earth-rocky mountain areas of North China were analyzed, and the characteristics and laws of its rainfall response recharge were revealed, aiming at providing a reference and theoretical basis for rational utilization of water resources and water conservation in this area. [Methods] This study focused on typical natural barren slopes in earth-rocky mountain area of North China, employing in-situ monitoring to collect real-time data on soil moisture at different slope positions for detailed analysis. The dynamic response characteristics of soil moisture to rainfall and its intrinsic patterns were studied. [Results] ① The average annual soil moisture content along the slope exhibited the following pattern: bottom slope (20.3%±5.5%) > top slope (19.5%±5.7%) > middle slope (15.9%±7.0%), and in the vertical profile, deeper soil layers had a higher moisture content than that in shallower layers. ② The response rate of soil moisture to rainfall was significantly faster in the middle slope (1.50 h) compared to that in the top (4.10 h) and bottom slopes (2.80 h), and in the vertical profile, deeper soil layers responded to rainfall more quickly than shallower layers. ③ The average rates of moisture replenishment and depletion due to rainfall were as follows: middle slope (1.4%/h, 0.3%/h) > top slope (0.9%/h, 0.2%/h) > bottom slope (0.7%/h, 0.1%/h), and in the vertical profile, the replenishment and depletion rates were higher in deeper soil layers than in shallower layers. [Conclusion] In the earth-rocky mountainous area of North China, when rainfall exceeds 2.7 mm, it can effectively recharge soil moisture on slopes. Additionally, the responses of the middle slope and deeper soil layers to rainfall were notably more rapid.