A video coding method using a multi-layer structure, and more particularly, a method and apparatus for facilitating a search for an intra-prediction mode in an upper layer using an intra-prediction mode in a lower layer while efficiently and compressively encoding the searched intra-prediction mode are provided. The intra-prediction method includes searching for an optimum prediction mode of a current block among a predetermined number of intra-prediction modes, and obtaining a directional difference between the searched optimum prediction mode and an optimum prediction mode of a lower layer block corresponding to the current block.