In this paper, we propose a methodological approach for the model driven development of secure XML databases (DB). This proposal is within the framework of MIDAS, a model driven methodology for the development of Web Information Systems based on the Model Driven Architecture (MDA) proposed by the Object Management Group (OMG) [20]. The XML DB development process in MIDAS proposes using the data conceptual model as a Platform Independent Model (PIM) and the XML Schema model as a Platform Specific Model (PSM), with both of these represented in UML. In this work, such models will be modified, so as to be able to add security aspects if the stored information is considered as critical. On the one hand, the use of a UML extension to incorporate security aspects at the conceptual level of secure DB development (PIM) is proposed; on the other, the previously-defined XML schema profile will be modified, the purpose being to incorporate security aspects at the logical level of the secure XML DB development (PSM). In addition to all this, the semi-automatic mappings from PIM to PSM for secure XML DB will be defined.