In the context of large-scale and rapid changes in coastal city ecosystems driven by recent urbanization, this research evaluated the ecological health status and trends of Xiamen City from 1996 through 2006 using the quantitative catastrophe progression method (CPM). The results show that CPM has less subjectivity than traditional methods in weight evaluation and uncertainty in estimating the standard of health subjectively. The ecosystem health curve of Xiamen City displays its first inflexion in 1999, which can be attributed to the large-scale and profound ecological disturbance from major projects such as sea reclamation and deforestation. The projects overstepped the ability of Xiamen City′s ecosystem to ecologically remediate the disturbance. The second inflexion of Xiamen City′s ecosystem health curve appears in 2001 due to the significant strategic transformation from its original island-based configuration to a new larger bay-area-based eco-city. CPM captures short-term changes in Xiamen City′s ecosystem under rapid urbanization, and provides an objective assessment of changes in Xiamen City′s ecosystem health.