This paper presents a process-based model for runoff generation on slopes. One dimensional kinematic wave theory combined with the revised Green-Ampt infiltration formula is applied in the model. According to the characteristics of soil and rainfall in the Loess Plateau area, six types of storm are defined, and among them three typical erosion zones that have different values of representative parameters are chosen to simulate the runoff generation processes. The primary hydraulic characteristics of the runoff generation, such as unit discharge, runoff depth, flow velocity, shear stress and ratio of runoff generation, are obtained and analyzed. The results demonstrate that the different erosion characteristics are related to different runoff generation zones. This paper presents a process-based model for runoff generation on slopes. One dimensional kinematic wave theory combined with the revised Green-Ampt infiltration formula is applied in the model. According to the characteristics of soil and rainfall in the Loess Plateau area, six types of storm are defined, and among them three distinct erosion zones that have different values ​​of representative parameters are chosen to simulate the runoff generation processes. The primary hydraulic characteristics of the runoff generation, such as unit discharge, runoff depth, flow velocity, shear stress and ratio of runoff generation, are obtained and analyzed. The results demonstrate that the different erosion characteristics are related to different runoff generation zones.