FIG. 9 shows an intra prediction method used for 4×4 block if a macroblock according to an embodiment of the present invention is 32×32 block. Specifically, a numeral represented in a block shown in FIG. 9 indicates encoding and decoding sequences of the corresponding block. Referring to FIG. 9a, if a size of a macroblock is 32×32, it is able to use one prediction mode for each 4×4 block. In particular, one most suitable prediction mode is selected from the 9 kinds of prediction modes shown in FIG. 8 for each 4×4 block and the selected prediction mode can be coded by 4×4 block unit. For instance, if an encoder selects a vertical prediction mode for a 0th block, encodes the selected prediction mode and then transmits the encoded prediction mode in FIG. 9a, a decoder decodes the 0th block using the received vertical prediction mode. Subsequently, a reconstructed residual is added to a prediction sample. A 1st block is then decoded using a vertical prediction mode equal to a prediction mode of the 0th block and the reconstructed 0th block. In this manner, decoding is performed on the entire 32×32 block.