An image decoding method including determining coding units having a hierarchical structure for decoding an image using split information of a coding unit, determining at least one prediction unit for predicting a coding unit among the coding units using information about a partition type, and determining at least one transformation unit for inversely transforming the coding unit using information about a depth of the at least one transformation unit, wherein the split information of a coding unit, the information about a partition type and the information about a depth of the at least one transformation unit are parsed from a bitstream, parsing from the bitstream transformation coefficients generated by transformation according to the at least one transformation unit generated by dividing the coding unit, and reconstructing residual of the at least one transformation unit by performing inverse quantization, and inverse transformation on the parsed transformation coefficients, and performing intra prediction or inter prediction on the prediction unit to generate a predictor, and reconstructing the image based on the residual and the predictor.