Provided are a video encoding method and a video decoding method according to spatial subdivisions based on splitting a picture into a first tile and a second tile, and splitting a current tile among the first tile and the second tile into at least one slice segment, encoding the first tile and the second tile, independently from each other, and encoding maximum coding units of a current slice segment among the at least one slice segment included in the current tile, with respect to the at least one slice segment included in the current tile.