A method of encoding an image, the method comprising: generating information about a division shape, to be used to determine a coding unit of a hierarchical structure included in a square maximum coding unit and including at least one of a coding unit of a current depth and a coding unit of a depth greater than the current depth; generating information about a prediction unit, to be used to determine at least one prediction unit which is split from the coding unit of a depth greater than the current depth; generating information about a prediction mode; generating information about a transformation unit, to be used to determine at least one transformation unit which is split from the coding unit of a depth greater than the current depth; performing inter prediction for the at least one prediction unit to generate a predictor; and generating quantized transformation coefficients of the at least one transformation unit generated by performing transformation and quantization based on residuals between the predictor and the image; wherein, the coding unit of the current depth is split into four equally sized square coding units of a depth greater than the current depth, independently from neighboring coding units of the current depth, and the coding unit of the depth greater than the current depth, among the four equally sized square coding units of a depth greater than the current depth, is predicted using the at least one prediction unit and is transformed using the at least one transformation unit, wherein the at least one prediction unit is one among blocks including: a block equal in size to the coding unit of the depth greater than the current depth; and a block among a plurality of blocks generated by equally dividing at least one of a height and width of the coding unit of the depth greater than the current depth, wherein the at least one transformation unit is one among blocks including: a block equal in size to the coding unit of the depth greater than the current depth; and a block among a plurality of blocks generated by equally dividing a height and width of the coding unit of the depth greater than the current depth, and wherein, when a prediction mode is determined to be an inter prediction mode, not an intra prediction mode, the method of encoding the image supports a transformation unit, included among the at least one transformation unit, having a size of 2N x 2N, that includes four prediction units, included among the at least one prediction unit, having a size of N x N. generating information about a division shape, to be used to determine a coding unit of a hierarchical structure included in a square maximum coding unit and including at least one of a coding unit of a current depth and a coding unit of a depth greater than the current depth; generating information about a prediction unit, to be used to determine at least one prediction unit which is split from the coding unit of a depth greater than the current depth; generating information about a prediction mode; generating information about a transformation unit, to be used to determine at least one transformation unit which is split from the coding unit of a depth greater than the current depth; performing inter prediction for the at least one prediction unit to generate a predictor; and generating quantized transformation coefficients of the at least one transformation unit generated by performing transformation and quantization based on residuals between the predictor and the image; wherein, the coding unit of the current depth is split into four equally sized square coding units of a depth greater than the current depth, independently from neighboring coding units of the current depth, and the coding unit of the depth greater than the current depth, among the four equally sized square coding units of a depth greater than the current depth, is predicted using the at least one prediction unit and is transformed using the at least one transformation unit, wherein the at least one prediction unit is one among blocks including: a block equal in size to the coding unit of the depth greater than the current depth; and a block among a plurality of blocks generated by equally dividing at least one of a height and width of the coding unit of the depth greater than the current depth, wherein the at least one transformation unit is one among blocks including: a block equal in size to the coding unit of the depth greater than the current depth; and a block among a plurality of blocks generated by equally dividing a height and width of the coding unit of the depth greater than the current depth, and wherein, when a prediction mode is determined to be an inter prediction mode, not an intra prediction mode, the method of encoding the image supports a transformation unit, included among the at least one transformation unit, having a size of 2N x 2N, that includes four prediction units, included among the at least one prediction unit, having a size of N x N.