Essential of BIM is management and interoperability of building information. This article demonstrated the principle of building information management. In managing information, principle is"by domain"; in sharing information, principle is"by practice". Information must be classified by domains, and each domain manage its information by itself. Common properties of building object are basis of BIM, special information used by domains are expansion. We not only emphasize consistency of information expression, but also pay attention to practicality of information using.This article illustrated the standpoint by application of BIM in PKPM software.