The energy and connectivity on the mobile devices in mobile peer-to-peer (MP2P) networks are limited. Since different mobile peers may store copies of shared information, the data synchronization on MP2P becomes crucial and challenging due to node mobility and limited resources. We propose effective approaches to solve the mentioned problem with a dynamic tree-like index structure and group-key agreement mechanism. The proposed approaches can effectively synchronize the data items and perform well in terms of the coverage of successfully synchronized nodes and the number of redundant messages. Last, we validate the proposed approaches through extensive simulation experiments and present our findings.