Abstract: To investigate the impacts of land use and landscape patterns at different temporal and spatial scales on water quality in Dongxi River, 1000 m river buffer zone and 200 m riparian buffer zone were selected. Based on the land use and landscape pattern of the buffer zone, combined with‌ the water quality of the river in the dry-rainy season, Redundancy Analysis (RDA) and Spearman Correlation Analysis was used to assess the spatiotemporal scale effects of land use and landscape pattern variables on water quality. The results showed that: (1) COD、NH₃-N、TN and TP exhibited the ‌positive correlation‌ with construction land and farmland, while demonstrating the ‌negative correlation‌ with forest land, patch density (PD), and Shannon diversity index (SHDI). (2) Construction land and farmland represent the most significant negative determinants of water quality , while land use exhibits a higher level of contribution for water quality than landscape pattern indicators (PD and SHDI). (3) The rainy season amplifies the impact of land use and landscape configuration on water quality, with temporal variations demonstrating heightened significance. Spatial scale analysis reveals that 200 m riparian buffer zone significantly influences water quality during the rainy season, with water as the primary explanatory variable, whereas a 1000 m river buffer zone along the river section becomes critical in the dry season, where construction land emerges as the dominant explanatory variable. Analyzing the key drivers and spatiotemporal scale effects of water quality provides critical insights for optimizing management strategies in the Xingyun Lake Basin and enabling precise control measures.