LIGN: justify">Taking Panxian County as a study case, the authors make a thorough analysis on regional karst rocky desertification assessments and their spatial scale impacts based on different grid units at 100 m×100 m, 200 m×200 m, 500 m×500 m, 1 000 m×1 000 m. The calculation of karst rocky desertification integrated assessment index (KDI) takes the percentage of areas and the patch assembles of grid units into consideration, which could reveals the spatial heterogeneity of karst rocky desertification. The results indicate that the KDI is influenced by assessment unit sizes, and there are some differences among assessment results of four spatial units and the actual distribution of karst rocky desertification.