A method of decoding a video, the method comprising: extracting, from a bitstream, information about a maximum size of a coding unit, and split information indicating whether a coding unit of a current depth is split into coding units of a lower depth; determining a plurality of maximum coding units by dividing a picture using the information about a maximum size of the coding unit; determining, based on the split information, coding units of a hierarchical structure comprising coding units which are not split any more among coding units split from each maximum coding unit among the plurality of maximum coding units; and decoding the coding units of the hierarchical structure in the each maximum coding unit, wherein: the each maximum coding unit is hierarchically split into coding units of depths including at least one of a current depth and a lower depth according to the split information, when the split information indicates a split for the coding unit of the current depth, the coding unit of a current depth is split into coding units of the lower depth by dividing a height and width of the coding unit of a current depth by two, characterized that: when the split information indicates a non-split for the coding unit of the current depth, a plurality of prediction units are determined in the coding unit of the current depth, inter prediction is performed on the plurality of prediction units, one or more transformation units are determined in the coding unit of the current depth and inverse transformation is performed on the transformation unit. extracting, from a bitstream, information about a maximum size of a coding unit, and split information indicating whether a coding unit of a current depth is split into coding units of a lower depth; determining a plurality of maximum coding units by dividing a picture using the information about a maximum size of the coding unit; determining, based on the split information, coding units of a hierarchical structure comprising coding units which are not split any more among coding units split from each maximum coding unit among the plurality of maximum coding units; and decoding the coding units of the hierarchical structure in the each maximum coding unit, wherein: the each maximum coding unit is hierarchically split into coding units of depths including at least one of a current depth and a lower depth according to the split information, when the split information indicates a split for the coding unit of the current depth, the coding unit of a current depth is split into coding units of the lower depth by dividing a height and width of the coding unit of a current depth by two, characterized that: when the split information indicates a non-split for the coding unit of the current depth, a plurality of prediction units are determined in the coding unit of the current depth, inter prediction is performed on the plurality of prediction units, one or more transformation units are determined in the coding unit of the current depth and inverse transformation is performed on the transformation unit. when the split information indicates a non-split for the coding unit of the current depth, a plurality of prediction units are determined in the coding unit of the current depth, inter prediction is performed on the plurality of prediction units, one or more transformation units are determined in the coding unit of the current depth and inverse transformation is performed on the transformation unit.