An artificial loess watershed is adopted to investigate the variation in slope landscape structure with loess watershed evolution. The evolution of the simulated loess watershed was driven by the exogenetic force of artificial rainfall. Quantitative indices of the slope landscape structure varied regularly following the evolution of the simulated loess watershed. Mean patch area (AREA_MN), and Patch Cohesion Index (COHESION) kept increasing following the evolution of the simulated watershed, while Perimeter-Area Fractal Dimension (PAFRAC), and Interspersion and Juxtaposition Index (IJI) showed an opposite trend. All the indices change actively in the early and active development periods, but changed slowly in the stable development periods.