The MPM may be determined by using a neighboring block of a current block. The neighboring block may mean a block which is adjacent to at least one of a left, a top, a top-left, a top-right or a bottom-right of a current block. The number of the neighboring blocks may be 1, 2, 3, 4, 5, or more. The number may be the fixed number which is predefined in an encoding/decoding device. The number may be variably determined based on a predetermined encoding parameter. The encoding parameter may include information on a block attribute. Herein, a block attribute may mean a position, a size, a shape, a ratio of a width and a height, a length value of a width and a height, a partitioning method (e.g., Quadtree, Binary tree, Ternary tree), a partitioning depth, a value of an intra prediction mode, whether an intra prediction mode is a directional mode, an angle of an intra prediction mode, a component type (luma, chroma), etc. Alternatively, the number may be encoded and signaled in an encoding device. The signaling may be performed in a level of at least one of a video sequence, a picture, a slice, a tile or a predetermined partial region (e.g., CTU row, CTU, CU, PU, etc.).