An apparatus for decoding an image in intra prediction can include an inverse scanning module generating a quantized block by applying an inverse scan pattern to significant flags, coefficient signs and coefficient levels; an inverse quantization module generating a quantization parameter predictor, adding the quantization parameter predictor to a differential quantization parameter to generate a quantization parameter and inversely quantizing the quantized block using the quantization parameter; an inverse transform module inversely transforming the inversely quantized block to restore a residual block; an intra prediction module generating a prediction block; and an adder generating a reconstructed block using the residual block and the prediction block, in which when a size of a transform unit is equal to or smaller than 8×8, the inverse scan pattern is a horizontal scan for a vertical mode and a predetermined number of intra prediction modes having closest direction to the vertical mode, the inverse scan pattern is a vertical scan for a horizontal mode and the predetermined number of the intra prediction modes having closest direction to the horizontal mode.