1. An apparatus for estimating a motion vector of a current block, the apparatus comprising: a partition selection unit which selects at least one of partitions, which are compared with the current block for obtaining a motion vector difference, among a plurality of candidate partitions around the current block; and a motion vector estimation unit which estimates a motion vector of the selected partition as an estimated motion vector of the current block and generates the motion vector difference, wherein the motion vector estimation unit transmits information on the motion vector difference, partition information for reconstruction of the motion vector of the current block, wherein the plurality of candidate partitions are determined from neighboring partitions around the current block based on a predetermined condition, and wherein the plurality of neighboring partitions comprise partitions of various sizes and a size of one of the plurality of neighboring partitions is different from the size of current block.