The present invention relates to an intra prediction scheme among video coding techniques and, more particularly, relates to a video decoding method and apparatus for diving a block into a plurality of sub-blocks when intra prediction is performed and sequentially performing infra prediction on each of the sub-blocks. The decoding method performed by a video decoding apparatus includes determining whether to perform sub-block-based intra prediction on a current coding unit, dividing the current coding unit into a plurality of sub-blocks, performing intra prediction on each of the sub-blocks when a result of determination of whether to perform sub-block-based intra prediction has a value of “true”, and directly performing block-based intra prediction on the current coding unit without dividing the current coding unit when the result of the determination has a value of “false”.