1. A moving picture decoding device with motion compensating prediction in units of block, comprising: a motion vector predictor candidate generating unit configured to, when a block size of blocks to be decoded is larger than a predetermined threshold size, include a motion vector predictor candidate derived from blocks in a decoded image into a motion vector predictor candidate list, and when the block size of the blocks to be decoded is smaller than or equal to the predetermined threshold size, configured not to include the motion vector predictor candidate into the motion vector predictor candidate list; a motion information candidate generating unit configured to, when the block size of blocks to be decoded is larger than the predetermined threshold size, include a motion information candidate derived from blocks in the decoded image into a motion information candidate list, and when the block size of the blocks to be decoded is smaller than or equal to the predetermined threshold size, configured not to include the motion information candidate into the motion information candidate list; a decoding unit configured to decode a merge flag indicating using a merge index or a motion vector predictor index, wherein the decoding unit is, when the merge flag indicates to use the merge index, configured to decode the merge index on a position of motion information to be referred to in the motion information candidate list, and when the merge flag indicates to use the motion vector predictor index, configured to decode the motion vector predictor index on a position of motion vector predictor to be referred to in the motion vector predictor candidate list; a motion information selecting unit configured to select motion information of the blocks to be decoded from the motion information candidate list based on information on the position of the motion information to be referred to in the motion information candidate list when the merge flag indicates to use the merge index; and a motion vector predictor selecting unit configured to select a motion vector predictor of the blocks to be decoded from the motion vector predictor candidate list based on information on the position of the motion vector predictor to be referred to in the motion vector predictor candidate list when the merge flag indicates to use the motion vector predictor index, wherein the blocks in the decoded image are blocks at the same positions as the blocks to be decoded or blocks neighboring the blocks at the same positions, and the decoded image is temporally different from an image including the blocks to be decoded, wherein a motion vector of the blocks in the decoded image is set to the motion vector of any one block in a predetermined region per predetermined region; and wherein the predetermined threshold size is set to be smaller than a size of the predetermined region.