Abstract: Western China presents an important barrier to maintaining national ecological security. Since the Western Development Strategy was implemented over 20 years ago, major ecological construction projects have led to significant changes in the ecological conditions and services in the western region. Exploring the ecological stability patterns in the western region is important for macroecological land management. This study analyzed the spatiotemporal dynamic changes in the ecological land stability index in the western region from 2000 to 2020 based on remote sensing monitoring data of land use/land cover. The results showed the following. 1) From 2000 to 2020, the total amount of ecological land in the western region decreased and then increased. From 2000 to 2010, the ecological land area decreased by 22 327 100 hm²; from 2010 to 2020, the area increased by 964 700 hm². The spatial distribution of stable ecological land did not change significantly during the two periods, with stable ecological land consisting mainly of grasslands and forests. 2) The overall ecological land stability indices in the western region from 2000 to 2010 and 2010 to 2020 were 47.12% and 52.72%, respectively. There was a significant clustering of ecological stability indices from 2000 to 2020. The ecological land stability pattern mainly comprised high-high and low-low clustering areas, accounting for 48.17% and 46.708%, respectively. Areas of high-high clustering and high-low outliers showed an upward trend, while low clustering and low-high outlier areas showed a downward trend. 3) The total cold spot area decreased by 1026 × 104 hm², and the total hot spot area increased by 206 × 104 hm², indicating that, while the ecological stability index in the western region is slowly improving, the agglomeration effect of stable ecological land has also improved.