The present invention discloses a method and an apparatus for indicating a channel in a wireless local area network WLAN. A sending station generates and sends a physical protocol data unit PPDU, the PPDU includes a preamble field and a data field, a high efficiency signal field HE-SIG-A of the preamble field includes a bandwidth identifier and a channel bonding identifier, and the channel bonding identifier is used to indicate whether a data transmission channel is continuous in a frequency domain. In the foregoing manner, a discontinuous channel in a frequency domain in a wireless local area network is indicated, an available channel for data transmission is improved, and a system throughput is increased.