1. A method for predictively decoding a motion vector used in motion compensated prediction to restore a video sequence consisting of a temporal sequence of frame pictures, comprising: a step of scanning, in an upward direction starting from a bottom of the left-neighboring region, one or more partitions included in the left-neighboring region to determine a first motion vector predictor candidate that satisfies a predetermined criterion used in determination of motion vector predictor candidates, from a motion vector or motion vectors of one or more partitions belonging to a left-neighboring region located on the left side of a target partition in a frame picture of a decoding target; a step of determining a second motion vector predictor candidate satisfying a predetermined criterion used in determination of motion vector predictor candidates, from a motion vector or motion vectors of one or more partitions belonging to an above-neighboring region located above the target partition; a step of decoding encoded data to restore motion vector predictor indication information specifying an optimum motion vector predictor for the target partition; and a step of selecting the optimum motion vector predictor specified by the motion vector predictor indication information, from one or more motion vector predictor candidates including at least the first motion vector predictor candidate and the second motion vector predictor candidate, wherein a predicted signal of the target partition is generated by referring to a reference frame with a frame number specified by a reference picture list identification and a reference picture identification, wherein the step of determining the first motion vector predictor candidate comprises determining the first motion vector predictor candidate from motion vectors of partitions in the left-neighboring region having a reference picture list identification and a reference picture identification coincident with the reference picture list identification and the reference picture identification for the target partition, and wherein the step of determining the second motion vector predictor candidate comprises determining the second motion vector predictor candidate from motion vectors of partitions in the above-neighboring region having a reference picture list identification and a reference picture identification coincident with the reference picture list identification and the reference picture identification for the target partition.