A motion vector decoding apparatus decodes a coded motion vector of a current block in a moving picture. The motion vector decoding apparatus includes a neighboring block specification unit specifying a neighboring block which is located in the neighborhood of the current block and has already been decoded; a judgment unit judging whether or not the neighboring block has been coded using a motion vector of another block; a prediction unit deriving a predictive motion vector of the current block using a motion vector calculated from the motion vector of the other block as a motion vector of the neighboring block, when it is judged that the neighboring block has been coded using the motion vector of the other block; and a decoding unit decoding the coded motion vector of the current block using the predictive motion vector.