Disclosed is an apparatus for decoding motion information in merge mode for reconstructing a moving picture signal coded at a low data rate while maintaining a high quality of an image. The apparatus for decoding motion information in merge mode discloses the position of a merge mode candidate and the configuration of a candidate in order to predict motion information in merge mode efficiently. Furthermore, a merge candidate indicated by the merge index of a current block can be efficiently reconstructed irrespective of a network environment by adaptively generating a merge candidate based on the number of valid merge candidate.