Provided is a method and apparatus for image intraprediction encoding/decoding. The method for image intraprediction encoding includes an intraprediction unit which divides an input block into at least one first sub-block of a predetermined size, and performing intraprediction encoding on the at least one first sub-block according to a first sub-block processing order using pixel values of at least adjacent sub-blocks located to the right of and/or below the at least one first sub-block.