According to one embodiment of the present specification, a method for determining a beam to be used by a terminal for communication in an mmWave communication system can be provided. Here, the method for determining a beam to be used by a terminal for communication may comprise the steps of: receiving a CSI-RS from a base station; reporting a preferred primary beam to the base station on the basis of the received CSI-RS; receiving secondary beam information from the base station on the basis of the preferred primary beam; reporting a preferred secondary beam from among the secondary beam information to the base station; and receiving a setting of a CSI-RS resource from the base station on the basis of the preferred secondary beam. Here, the secondary beam information may include the preferred primary beam and at least one secondary beam to which QCL is applied.