A decoding method and a decoder for decoding a current block of a video is provided, wherein the decoding method comprises: determining a set of Most Probable Modes (MPMs) for the current block. When at least one condition is satisfied, the set of MPMs includes a Planar mode, a DC mode, a Vertical mode, a Horizontal mode, an intra prediction mode corresponding to a value of the Vertical mode with a first offset, and an intra prediction mode corresponding to the value of the Vertical mode with a second offset. The decoding method further includes obtaining a MPM flag and an MPM index for the current block from a bitstream of the video, and obtaining an intra prediction mode for the current block for reconstructing the current block.