Embodiments of the present invention relate to the communications field, and provide a CQI measurement method, an apparatus, and a wireless communications system, to improve accuracy of downlink CQI measurement performed by UE. The CQI measurement method includes: determining, by a base station, a downlink CQI measurement resource, where the downlink CQI measurement resource is for use by a first UE to perform downlink CQI measurement, the downlink CQI measurement resource includes a frequency domain resource, and a bandwidth of the frequency domain resource is less than a system bandwidth; and sending, by the base station, resource indication information to the first UE, where the resource indication information is used to indicate the downlink CQI measurement resource.