A video decoding method involving intra prediction includes: parsing a most probable mode (MPM) flag of a block while parsing symbols of the block of an encoded video from a received bitstream; determining whether a predetermined number of a plurality of candidate intra prediction modes are used to predict an intra prediction mode of the block based on the MPM flag; when it is determined that the plurality of candidate intra prediction modes are used based on the MPM flag, determining the plurality of candidate intra prediction modes based on intra prediction modes of a left block and an upper block that are adjacent to the block while restoring the intra prediction mode of the block by using the parsed symbols.