The present invention relates to a wireless communication system and, more specifically, to a method and an apparatus for determining an operating channel. The method for determining the operating channel of a station (STA) in a TV whitespace (TVWS) wireless LAN system, according to one embodiment of the present invention, comprises the steps of: receiving information on an index which indicates an operating class including channel start frequency, channel spacing, and channel set parameters; and determining a main frequency of the operating channel on the basis of the parameters indicated by the index of the operating class. The main frequency of the operating channel can be determined on the basis of a correction value which is set differently according to the configuration of a basic channel unit of the operating channel.