A picture decoding apparatus which decodes a bit stream of a coded picture, the picture decoding apparatus comprising: a bit stream receiving unit configured to receive an input bit stream; a decoding unit configured to decode the input bit stream, which is received, to obtain a first transform block and an adjacent second transform block in a reconstructed picture including a plurality of macroblocks, said first and second transform blocks being a unit for which a frequency transformation is applied and being motion-compensated; a coding distortion removal unit configured to remove a coding distortion of each of the plurality of macroblocks in the reconstructed picture; and a storing unit configured to store the reconstructed picture for which a coding distortion is removed, characterized in that: when (i) a block size of a motion-compensation block is smaller than a block size of the macroblock and a block size of the motion-compensation block is greater than a block size of the transform blocks and (ii) two adjacent motion-compensation blocks included in one macroblock have a coded motion compensation error equal to zero, the coding distortion removal unit is further operable to: remove the coding distortion in pixels in a block boundary between the first transform block and the adjacent second transform block when the first block is located in a first one of the two adjacent motion-compensation blocks and the adjacent second transform block is located in the second one of the two adjacent motion-compensation blocks, and not remove the coding distortion in pixels in a block boundary between the first transform block and the adjacent second transform block when the first transform block and the adjacent second transform block are located inside one of the two adjacent motion-compensation blocks, wherein the motion-compensation block is a unit for which a motion compensation is applied. a bit stream receiving unit configured to receive an input bit stream; a decoding unit configured to decode the input bit stream, which is received, to obtain a first transform block and an adjacent second transform block in a reconstructed picture including a plurality of macroblocks, said first and second transform blocks being a unit for which a frequency transformation is applied and being motion-compensated; a coding distortion removal unit configured to remove a coding distortion of each of the plurality of macroblocks in the reconstructed picture; and a storing unit configured to store the reconstructed picture for which a coding distortion is removed, characterized in that: when (i) a block size of a motion-compensation block is smaller than a block size of the macroblock and a block size of the motion-compensation block is greater than a block size of the transform blocks and (ii) two adjacent motion-compensation blocks included in one macroblock have a coded motion compensation error equal to zero, the coding distortion removal unit is further operable to: remove the coding distortion in pixels in a block boundary between the first transform block and the adjacent second transform block when the first block is located in a first one of the two adjacent motion-compensation blocks and the adjacent second transform block is located in the second one of the two adjacent motion-compensation blocks, and not remove the coding distortion in pixels in a block boundary between the first transform block and the adjacent second transform block when the first transform block and the adjacent second transform block are located inside one of the two adjacent motion-compensation blocks, wherein the motion-compensation block is a unit for which a motion compensation is applied. remove the coding distortion in pixels in a block boundary between the first transform block and the adjacent second transform block when the first block is located in a first one of the two adjacent motion-compensation blocks and the adjacent second transform block is located in the second one of the two adjacent motion-compensation blocks, and not remove the coding distortion in pixels in a block boundary between the first transform block and the adjacent second transform block when the first transform block and the adjacent second transform block are located inside one of the two adjacent motion-compensation blocks, wherein the motion-compensation block is a unit for which a motion compensation is applied.