Recently, many online games have been developed by improvement of network technology in consumer game machines and portable game machines. Typical network game architecture is based on clientserver model and Hybrid-P2P model. Because of heavy resource needs in servers, it is not easy to develop network games in game providers. We propose a platform based on overlay network which does not need the server for the online game, and develop a common platform in online game. This platform?s name is SNEO (non Server Network game Environment by using Overlay network) .Game provides can share the common platform in various games. Game providers become possible to produce games without considering about the load of networks and servers. In this paper, it proposes the outline of our platform, and the opponent matching protocol which becomes essence in online games.