To accommodate the increasing air traffic and increase safety and efficiency of aviation operation, ICAO (International Civil Aviation Organization) recommended the development and implement of a new CNS/ATM system which is based on GNSS technologies and data link communication. The system is composed of Communication, Navigation, Surveillance and Air Traffic Management. ICAO approved the Global Air Navigation Plan for CNS/ATM systems. The world aviation leader countries launched CNS/ATM Research and Development program to enable the Global Plan and support the transition of air traffic infrastructure. In this paper, to establish the direction and measures of domestic technology development, CNS/ATM technology trend is analyzed.