Abstract: IMT-Advanced is a tentative name used for the fourth-generation mobile communication system, which is the successor system to IMT-2000. In order to provide higher data rate and solve the issues which limit development of wireless communication system, IMT-Advanced should make breakthrough in notions and technologies. This paper starts by analyzing the principal characteristics of IMT-Advanced system, and then brings forward three problems which should be solved emergently. Indubitably, how to address the Base Stations, how to reduce transmission power, and how to allocate the frequency band are the inextricable problems to next generation communication systems. Finally, the potential key technologies related are analyzed briefly.