The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). An operation method of a receiving device in a wireless system includes receiving a polar codeword generated by a polar code, generating a majority of decoding paths by decoding a bit value corresponding to one index that is selected among a majority of indexes indicating respective bits included in the polar codeword, determining a first candidate group that includes at least one decoding path among the majority of decoding paths, and determining, as a second candidate group, at least one decoding path passing a CRC check among the first candidate group. A number of the at least one decoding path included in the first candidate group is determined based on a result of a CRC check performed prior to the CRC check.