This paper proposes a new approach to calculate eco-efficiency in industrial parks, namely, carrying capacity analysis. Such a method could be applied to calculate the current sustainable development level of an industrial park and therefore build up a solid foundation for industrial park management to make their sustainable development strategies. A case study approach is employed at Dalian Economical and Technical Development Zone in order to test its feasibility and applicability. The result of this case study has indicated that this method is a useful tool to help industrial park management recognize their development issues of when considering their own realities.