A method performed by a video encoding apparatus, includes: encoding block mode information indicating whether a block mode of a current block to be decoded is a skip mode; when the block mode of the current block is the skip mode, encoding a skip motion information of the current block without encoding information on residual signals of the current block, wherein the skip motion information is used for determining a motion vector of the current block; and when the block mode of the current block is not the skip mode, encoding prediction information of the current block, and encoding partition information of a tree structure related to dividing the current block into one or more subblocks, and thereby encoding information on residual signals of the subblocks.