A device for encoding a picture included in moving picture data, through motion compensation, the device includes, a storage unit for storing a motion vector for motion compensation, the motion vector determined for each of a plurality of encoded pictures, a picture interval comparator for reading from the storage unit a first motion vector as a standard candidate vector, a co-located vector decider for calculating a co-located vector by setting the standard candidate vector to be the co-located vector of the first block, a direct motion vector calculator for calculating a first direct motion vector and a second direct motion vector with respect to the first block by dividing the co-located vector, a prediction image generator for generating a first motion compensation image, and an encoder for encoding an error signal representing a difference between the prediction image and a corresponding pixel on the first block.