The present disclosure relates to the field of mobile communication, and in particular, to frequency determining technologies in the field of wireless communication. In a frequency determining method, a base station determines a frequency according to different modes, so that an interval between the frequency and a channel raster is not greater than a particular threshold. Corresponding frequencies are determined by setting different thresholds. According to the technical solutions provided in this application, user equipment may determine, in different modes, a corresponding frequency resource to communicate with a base station.