Architectural complexity analysis plays an important role in the design of complex systems and System of Systems (SoS). In this process, a central problem is how to define the complexity indicator in the SoS level. This paper discusses a preliminary study on the architectural complexity analysis of the BRIDGE system, a typical large-scale emergency rescue management system. The traditional definition of architectural complexity, which has been successfully used to describe the architectural complexity of military SoS, is not suited for this case. The definition of architectural complexity, which consists of the multiplication of several components of complexity indicators, does not consider the varying importance of each component in different types of complex systems and SoS. This paper proposes a more general definition of architectural complexity by introducing additional exponential weighting factors to model such domain-related effects. Expert ratings on the relative importance of pair-wise components to the architectural complexity are used to estimate these weights. The new definition of architectural complexity facilitates the incorporation of the subjective domain-related knowledge and thereby provides a more flexible and reasonable measurement on the architectural complexity of complex systems and SoS.@en