Abstract: With many low-power nodes deployed in the network, LTE-Advanced system becomes more complicated. PCI automatic allocation, as a key step before system operation, plays an important role in network planning and promoting system performance. Reasonable PCI is of great importance to cell search and synchronization. A PCI automatic allocation method, which is based on the nearest-distance and farthest-distance simultaneously, was proposed. By this method, PCI could be allocated reasonably, and synchronization signal interference could be avoided efficiently, with system performance promoted. System level simulation results show that，the proposal method performs much better in terms of both sector average spectrum efficiency and cell edge user’s spectrum efficiency, compared with the classical sequential PCI allocation.