Abstract: The evaluation of ecological carrying capacity is the important reference for optimizing the project plans and promoting the sustainable development of socio-economy and natural environment. However most of the available evaluation methods of ecological carrying capacity are incompetent in project pertinence. The methods are basically used to study the comprehensive and regional resource and environmental problems, but not suitable for assessing the sustainable carrying capacity of natural resource and eco-environment systems for specific types of project construction within the planning area. Taking Xiamen Bay as an example, the RS and GIS technologies were applied and the principle of ecological suitability evaluation used to constitute the evaluation index system and explore the ecological capacity evaluation technique for the coastal port development, based on coastline habitat conservation of important species and in combination of the constraint conditions for the development. The research can enhance the technical supports ability of the evaluation results in improving the project schemes, and promote to reform the ecological capacity evaluation technologies for project plans.