We address the revision problem for knowledge bases (KBs) in Description Logics (DLs). This problem has received much attention in the ontology management and DL communities, but the existing proposals are restricted in several ways. In this paper we develop a formal framework for revision of DL-Lite KBs, using techniques that are analogous to those for model-based revision in propositional logic. However, unlike propositional logic, a DL-Lite KB can have infinitely many models, which makes it hard to define and compute revision in terms of models. For this reason, we first develop an alternative semantic characterization for DL-Lite by introducing the concept of a feature and then define a specific revision operator for DL-Lite KBs based on features (instead of models). In contrast to previous approaches, we tackle the problem of revision between KBs, and the result of revision is always an unique DL-Lite KB. We also present an algorithm for computing KB revisions in DL-Lite.