Abstract. We developed a reliable mobile Peer-to-Peer (P2P) data sharing system and performed some experiments for verifying our routing scheme using our real testbed. Our method for guaranteeing reliable P2P data sharing mainly deals with the problem of disconnection due to the sudden disappearance of one or more nodes involved in the active transmission route. The routing scheme of our system allows for reliable transmission of data via mobile devices. It does this using our reconnection mechanism that finds emergency routes in instances of abrupt disconnection using our scanning table and lookup table. The experiments lead us to conclude that our communication method is effective and assures reliable P2P data sharing over mobile ad hoc networks. In addition, our system allows for finding directly connectable devices at the overlay networks, therefore the application program can distinguish whether the target node is directly accessible or not with the aid of our scanning table.