Abstract: In ubictuitous computing environment,it is a important research to model the context aware systems formally. Firstlly, we discussed applicability and deficiency of a extended bigraphical model of context-aware systems called Polato Graphical Model. On the basis of analysis of Polato Graphical Model, we presented a calculational biographical model for description of context aware systems and compared it with Polato Graphical Model through an example.

Key words: Bigraphs theory, Bigraphs reactive systems, Context aware, Formal models