A video decoding method comprising: obtaining, from a bitstream, transformation-unit hierarchical-structure information comprising maximum split information for a transformation unit with an intra mode, maximum split information for a transformation unit with an inter mode and information about a prediction mode for a coding unit, wherein the maximum split information for the transformation unit with the intra mode is a total number of allowable levels of transformation units with respect to a coding unit predicted according to the intra mode, wherein the maximum split information for the transformation unit with the inter mode is a total number of allowable levels of transformation units with respect to a coding unit predicted according to the inter mode, and wherein the maximum split information for the transformation unit with the intra mode and the maximum split information for the transformation unit with the inter mode are separately determined; when the information about the prediction mode indicates that the coding unit is predicted according to the intra mode, determining a maximum split level of a transformation unit based on the maximum split information for the transformation unit with the intra mode; determining transformation units in the coding unit predicted according to the intra mode, by using the maximum split level of the transformation unit and information about a partitioning type of the coding unit, wherein a size of the transformation units are equal to or less than a size of partitions determined in the coding unit predicted according to the intra mode; performing inverse-transformation on the coding unit predicted according to the intra mode by using the transformation units. obtaining, from a bitstream, transformation-unit hierarchical-structure information comprising maximum split information for a transformation unit with an intra mode, maximum split information for a transformation unit with an inter mode and information about a prediction mode for a coding unit, wherein the maximum split information for the transformation unit with the intra mode is a total number of allowable levels of transformation units with respect to a coding unit predicted according to the intra mode, wherein the maximum split information for the transformation unit with the inter mode is a total number of allowable levels of transformation units with respect to a coding unit predicted according to the inter mode, and wherein the maximum split information for the transformation unit with the intra mode and the maximum split information for the transformation unit with the inter mode are separately determined; when the information about the prediction mode indicates that the coding unit is predicted according to the intra mode, determining a maximum split level of a transformation unit based on the maximum split information for the transformation unit with the intra mode; determining transformation units in the coding unit predicted according to the intra mode, by using the maximum split level of the transformation unit and information about a partitioning type of the coding unit, wherein a size of the transformation units are equal to or less than a size of partitions determined in the coding unit predicted according to the intra mode; performing inverse-transformation on the coding unit predicted according to the intra mode by using the transformation units.