The present disclosure relates to channel state reporting in wireless communications. According to an embodiment of the present disclosure, a method performed by a first wireless device in a wireless communication system comprises: establishing a PC5 radio resource control (RRC) connection between the first wireless device and a second wireless device; receiving sidelink control information (SCI) from the second wireless device, wherein the SCI instructs the first wireless device to perform sidelink (SL)-channel state information (CSI) reporting for the PC5 RRC connection; triggering the SL-CSI reporting; and based on that a sidelink resource for the SL-CSI reporting is unavailable and the first wireless device is configured with a mode in which sidelink resources are scheduled by a network, transmitting a signal related to the SL CSI reporting for requesting the sidelink resource to the network.