||We are interested in this thesis to the problem of access to distributed and heterogeneous data sources. In this context, we aim to develop a full service approach which leans on a new pattern of service that we call multimedia web services (MaaS : Multimedia as a Service). A multimedia service is capable of finding all type of data (image, text, video, etc.). It contributes to realize a service oriented architecture allowing to answer MSSD (Multi-sources, multi-Sites and multi-Domains) user queries. This architecture provides the possibility to access, to aggregate and to filter data according to the needs for the user.