This paper describes P2P platform implementation on PDAs. Recent progress of P2P and mobile technologies is promoting P2P platform on mobile devices which enables mobile devices to behave autonomously as peers within either hotspot or ad hoc wireless network. The implementation on PDAs requires new techniques quite different from those on PCs because of so poor resources. In view of this, we describe issues, solutions and evaluation results on the implementation of P2P platform on PDAs based on actual development. This result is expected to be useful for the implementation of P2P platforms on mobile devices hereafter.