The present invention relates to the field of communications technologies, and discloses a spectrum processing method, a base station, user equipment, and a system. The method includes: receiving, by a base station corresponding to a first cell, at least one subband channel quality parameter that is sent by user equipment (UE) in the first cell, where each subband channel quality parameter indicates quality of one subband channel; and determining, according to the at least one subband channel quality parameter, whether the first cell uses an overlapped spectrum, where the overlapped spectrum is a part at which a frequency band of the first cell overlaps a frequency band of a second cell, the second cell and the first cell are inter-system cells, and the second cell is neighboring to the first cell. The present invention is mainly applied to a process of using a network spectrum.