A coefficient access method includes: receiving a coefficient generated from an entropy decoding process, wherein the received coefficient is a part of a transform block (TB); before the received coefficient is stored into an inverse scan (IS) storage device, determining a storage position of the received coefficient according to a transpose flag associated with the TB, wherein the transpose flag indicates whether or not a coefficient transpose process is needed; and after the storage position is determined, storing the received coefficient into the determined storage position in the IS storage device.