Method and system for allocating physical cell identifiers

The embodiment of the invention discloses a method and a system for allocating physical cell identifiers (PCI), which can greatly reduce the probability of PCI conflicts and realize automatic configuration of the PCI. The method provided by the embodiment comprises the following steps of: allocating a temporary PCI to a newly-activated cell from a first PCI list; performing automatic neighborhood relation (ANR) detection by the newly-activated cell to acquire an operation PCI used by a neighborhood of the newly-activated cell, wherein the newly-activated cell comprises a direct neighborhood and a direct neighborhood of the direct neighborhood; and allocating a PCI different from the operation PCI used by the neighborhood to the newly-activated cell from a second PCI list, wherein the PCIs in the first PCI list are different from that in the second PCI list.