The tactical datalink system has been recognized as the key element in Network Centric Warfaret(NCW). The military has been putting great efforts into establishing datalink system using existing tactical radio and UMPC. but the aircraft operational environment and the requirement specification for equipments mounted in the avionics are differentiated with those in other platforms, so special efforts are needed to select suitable UMPC. In this paper, we consider the requirement analysis for UMPC in respect of processor performance, operation system (OS) and NVG compatibility. Additionally we have to make a effort to understand the operational environment of aircraft and examine th standard to select the appropriate UMPC, and then we expect to establish the tactical datalink system successfully.