Access to distributed, heterogeneous and autonomous information sources, becomes possible with the Internet. These information sources are distinguished by the nature of information, namely, the ontological domain to which they belong but also by the type of media they are issues, such as image, text, video, etc. With the advent of semantic web, new opportunities in multi-sources integration are emerging and many approaches are revisited with taking into account the new requirements. Also, there is the use or reuse of datawarehouses, mediators and peer-to-peer systems. Our project aim to propose a distributed and open system for indexing and searching multimedia content (DIOSYS) and especially an integration system based on the Peer-to-peer paradigm. In this study, we propose a state of the art of the integration problem by examining the most representative approaches of the three currents and we will try to summarize this study with use of tables after having presented and justified a set of criteria.