Abstract: The study of landscape pattern evolution is an important way to understand regional ecologicalsecurity and sustainable development. This study uses Landsat series remote sensing images from 2000 to2020, combined with Fragstats 4. 2 software to calculate landscape paltern indices. It also employsmethods such as the transfer matrix and geographic detector to systematically reveal the spatiotemporal e-volution characteristics and driving mechanisms of the landscape pattern in Chengjiang City. The resultsshow that: (1) From 2000 to 2020, the land coverage types in Chengjiang City were dominated by culti-vated land and forest land. Over the 20 - year period, the cultivated land area has decreased by 6. 54km2, most of which was converted to grassland and forest. The forest area increased by 36. 81 km2,mainly from cultivated land, while the construction land area increased by 5. 15 km2, mainly from culti-vated land and forest land. (2) Between 2000 and 2020, the degree of landscape fragmentation inChengjiang City intensified, with both the Contagion Index and Shannon's Diversity index showing upwardtrends, indicating that human activities have led to increased landscape heterogeneity. This study vali-dates the applicability of Fragstats in landscape analysis of plateau lake areas and provides data supportfor the land space optimization and ecological protection in Chengjiang City.

Key words: landscape ecology, Landscape pattern, Landscape index, drive, Chengjiang City