We propose a designing method of Web application based on the new standard XML and on the dataweb notion. The content of the dataweb is obtained by an integration technique of heterogeneous data sources through a model called structural. The dataweb content is diffused through the Web according to a method leaned on a media model. The method consists to define at first the media model that is a view of the structural model and generate next the media base. A presentation model describes the user interface where each media object is associated with a presentation. In this paper, we are interesting in the structural and media models. Key words: Web application, dataweb, designing method, XML