Granular computing is a new computing model, it relates to the methods of problem solving. Granular computing may be studied based on two basic related issues, i.e., the construction of granule and the computing of granule. In this paper, using rough set as tools, based on information system, a framework of granular computing has been provided. We defme the granular language and its semantics, the granule calculus has define with logical connectives in this paper too. The application in data mining of granular computing has been discussed.