Abstract: The Hangzhou Bay reclamation area is a human activity site formed due to its natural resources. Given that this area is a typical reclamation area along China's eastern coast, determining its ecosystem evolution holds significant scientific value for understanding the coupling mechanisms between human activities and land in a coastal zone. Under the combined effects of natural and anthropogenic factors, this area exhibits a highly dynamic land use pattern. This study aims to systematically elucidate the spatiotemporal evolutionary pattern of the ecosystem in this area under the driving force of reclamation activities. Based on the Landsat images of a long time series ranging from 2000 to 2024, this study conducted a comprehensive analysis using a decision tree-corrected classification method combined with multiple ecological indicators. The results indicate that the northern and southern shores of the Hangzhou Bay exhibited significantly different evolutionary paths of land use patterns. For the southern shore, the habitat quality index decreased substantially by approximately 14.63% during the early stage (2000-2015) due to intense development activities. For the northern shore, ecological restoration was implemented after 2015, reducing the rate of increase of built-up areas to approximately half that of the southern shore. As a result, the ecosystem on the northern shore gradually recovered. From 2000 to 2024, the comprehensive land use intensity index and carbon stocks per unit area presented an upward trend with fluctuations. The habitat quality alternated between degradation and restoration in response to ecosystem disturbances, reflecting the prolonged exploration of the dynamic balance between economic growth and ecological protection across the reclamation area. Overall, the results of this study provide a scientific basis for formulating ecological regulation strategies for coastal reclamation areas, holding great practical significance for the sustainable development of these areas.