A method of transmitting and receiving a data channel by a user equipment (UE) in a wireless communication system is disclosed. The method includes receiving downlink control information (DCI) including information related to a resource region for a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH), acquiring a resource indication value (RIV) from the DCI, acquiring a first length of allocated resource blocks based on the RIV, scaling the first length of allocated resource blocks to a second length of allocated resource blocks, based on a scaling factor and receiving the PDSCH or transmitting the PUSCH based on the second length of allocated resource blocks, wherein the scaling factor may be 2n, and n may be non-negative integer.