Disclosed is a method for encoding a motion vector by using spatial division, the method comprises: aggregating predicted motion vector candidates of a current block into a plurality of groups; selecting representative predicted motion vectors for respective groups by selecting one of aggregated predicted motion vector candidates within the respective groups as representative predicted motion vector; selecting single representative predicted motion vector from the representative predicted motion vectors for the respective groups as a predicted motion vector; and encoding a differential vector representing difference between a current motion vector of the current block and a selected predicted motion vector.