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 apparatus and a method for channel encoding and decoding in a communication or broadcasting system is provided. According to the present disclosure, the method for channel encoding in a communication or broadcasting system includes determining a block size Z, and performing encoding based on the block size and a parity check matrix corresponding to the block size, in which the block size is included in any one of the plurality of block size groups and the parity check matrix is different for each block size group.