This thesis elaborates the Model-Driven Software Modernization (MDSM), that has been identified by us, and is defined as a group of approaches toward modernization of legacy code. MDSM approaches are based on models, tools and processes known from the Model-Driven Engineering (MDE) that aims in automation of modernization process. This thesis describes identified MDSM approaches and related standards. Additionally, it suggests that certain kinds of modernization can be implemented in a more efficient way, when a new approach, that has been proposed by the authors, is used. An exemplary modernization, that solves selected industry problem, is implemented to demonstrate that the alternative approach is feasible. In addition, the availability of tools for MDA, which can be adopted in MDSM process, is discussed and guidelines for implementing MDSM are proposed.