A beam group reporting method is proposed. The network node may allocate a report configuration for the UE and transmit the allocated report configuration to the UE. The UE may perform the measurement based on the report configuration from the network node and determine at least one beam group based on a resource set associated with the report configuration and the measurement result. Each beam group may comprise two reference-signal (RS) resources respectively associating with different physical cell indexes (PCIs). Then, the UE may report a report comprising at least one beam group to the network node.