Provided is a frequency sensing method and apparatus in an orthogonal frequency division multiplexing (OFDM) system. Provided is a method of sensing a frequency of a received signal that is received from an outside in order to perform one of a plurality of radio communications. An OFDM apparatus may need to inspect a required frequency band before or after performing one of the plurality of radio communications, and to determine whether the frequency band is being used by another radio communication.