Adaptive Web systems apply page synthesis techniques to increase the flexibility of adaptation. Page synthesis process uses various system models, such as concept model, user model, and presentation model to generate the final presentation. The authors of an adaptive Web system need to express these models in a simple and reusable way. In this paper, a new language is proposed for presentation description to be used in an adaptive Web systems framework. The syntax of the language as well as its semantics has been defined and the implementation of a compiler for the language is discussed.