The Internet is playing an important role not only in information retrieving, but also in industrial processes manipulation. This paper describes an approach to writing requirements specification for Internet-based control systems and to deriving architecture for this new type of control systems according to the requirements specification. Specification is described in terms of a functional model and then extended into information architecture. Distinct from the functional model, the information architecture gives an indication to the architecture of the Internet-based control systems. An integrated-distributed architecture has been derived from the functional model and the information architecture as a case study.