The present disclosure relates to a method and apparatus for encoding/decoding a motion vector and a method and apparatus for encoding/decoding video using same. The motion vector encoding method includes selecting a predicted motion vector candidate set including one or more predicted motion vector candidates for a block; determining one or more search ranges for predicted motion vector candidate set; selecting one predicted motion vector candidate among one or more predicted motion vector candidates as predicted motion vector for each search point with respect to each search point within search range by first determination criterion prearranged with video decoding apparatus; selecting one predicted motion vector among the predicted motion vectors for each search point by a second determination criterion not prearranged with the video decoding apparatus, and determining predicted motion vector, differential motion vector, and current motion vector; and generating and encoding the differential motion vector as motion information.