Abstract: Water scarcity is a critical constraint on the sustainable development of arid river basins. Changes in basin water conservation capacity under climate change and human interference significantly impact future regional development potential and regional ecological patterns security. This study focuses on the Wuhai catchment which is the basin upstream of the first hydrological station on the Yellow River in Inner Mongolia. The spatiotemporal evolution and response between the landscape pattern and water conservation capacity in the basin was concerned in this research. Results indicate that from 2000 to 2020, the landscape pattern of the Wuhai catchment improved significantly, accompanied by positive trends in local climate and moisture conditions. The water yield in catchment exhibited a fluctuating increase. The result also suggested that interannual water conservation capacity was significantly influenced by precipitation fluctuations, while long-term trends were demonstrably affected by human activities and landscape pattern evolution. The area of bare land and grassland significantly impacted water conservation. Furthermore, water conservation demonstrated an interactive and enhanced relationship with key landscape metrics, including PLADJ, AI, LPI, IJI, and SHEI. Consequently, future ecological restoration efforts aiming to enhance water conservation capacity should transition from primarily adjusting landscape composition towards optimizing spatial pattern configuration. This study aims to elucidate the response mechanisms linking water conservation and landscape pattern in arid river basins, providing a theoretical foundation for improving basin water conservation function and optimizing landscape patterns.