The present disclosure relates to a 5G or pre-5G communication system for supporting a higher data transmission rate beyond the 4G communication system such as LTE. A decoding method using a polar code according to an embodiment of the present disclosure comprises the steps of: determining a first function for decoding input bits and a second function, which is independent from a log likelihood ratio (LLR) value of a previous input bit by the first function; and decoding the input bits in parallel using the first function and the second function. Also, the method comprises the steps of: determining an internal frozen bit using at least one input frozen bit which has a predetermined value of a predetermined position from among the input bits; and determining LLR values for layer bits sequentially from the higher layers of N layers.