Provided is a video decoding method including determining a reference intra prediction mode, based on availability and a prediction mode of an adjacent block of a current block; determining a plurality of candidate intra prediction modes for the current block, based on the reference intra prediction mode; obtaining, from a bitstream, intra prediction data comprising information regarding an intra prediction mode of the current block; when the intra prediction data indicates that the current block is predicted according to one of the plurality of candidate intra prediction modes, selecting an intra prediction mode to be used in intra predicting the current block, wherein the intra prediction mode is from among the plurality of candidate intra prediction modes; and performing intra prediction on the current block, according to the selected intra prediction mode.