Abstract: Coastal zone habitats have among the highest productivities and biodiversities throughout the world. Protecting marine ecosystems and resources demands the study and development of techniques to diagnose coastal zone habitat degradation. This is also critical to provide support for coastal environmental management. In this paper, the coastal zone of the Bohai Bay was selected as the study area, and the DPSIR framework model was adopted to establish an index system for diagnosing the coastal zone habitat degradation of the Bohai Bay. An analytic hierarchy process was applied to identify the weightings, so as to perform a comprehensive diagnosis and evaluation of the coastal zone habitat degradation of the Bohai Bay. The diagnostic results indicate that, compared with the 1980s, the water quality has degraded by one level; the sediment and the tidal flat habitat have degraded by two levels; the marine environmental pressure of the pollutant flux to the coastal zone has increased by two levels; and, the integrated state of the coastal zone of the Bohai Bay has degraded by one level.