Currently, the natural expectation of contracting a set of Web services by virtue of their semantics is becoming more and more feasible and popular. Meanwhile, it is generally accepted that a formalism with a well-defined model-theoretic semantics (i.e. some sort of logics) should be considered as the underpinning of Semantic Web Services . In this paper, concrete domain and action theory are incorporated into a very expressive DL, called ALCQO. Notably, this extension can significantly augment the expressive power for modeling and reasoning about dynamic aspects of services contracting. At the same time, the original nature and advantages of classical DLs, particularly the ability to describe "static" aspects of Web services, are also preserved to the extent possible.