A method of video decoding, the method comprising: obtaining merge flag and index information for a current block from a bitstream; determining a merge mode that is applied for the current block based on the merge flag indicating whether the merge mode is applied to the current block; deriving merge candidates for the merge mode from candidate blocks used for the merge mode of the current block; selecting one of the merge candidates to derive motion information of the current block based on the index information; deriving the motion information of the current block based on the selected merge candidate; deriving prediction samples on the current block based on the derived motion information; and generating reconstructed samples on the current block based on the prediction samples, wherein the candidate blocks used for the merge mode are searched in a region in which candidate blocks used for a mode using motion vector predictor, hereafter referred to as AMVP mode, are searched, wherein the merge mode is an inter prediction mode in which a motion vector of a candidate block for the merge mode is used as a motion vector of the current block, wherein the AMVP mode is an inter prediction mode in which a motion vector of a candidate block for the AMVP mode is used as the motion vector predictor for the current block, and wherein the candidate blocks used for the merge mode and for the AMVP mode include a first neighboring block located in a left side of the current block, a second neighboring block located in an upper side of the current block, a third neighboring block located at the bottom left corner of the current block, a fourth neighbor block located at the top right corner of the current block, and a fifth neighboring block located at the top left corner of the current block. obtaining merge flag and index information for a current block from a bitstream; determining a merge mode that is applied for the current block based on the merge flag indicating whether the merge mode is applied to the current block; deriving merge candidates for the merge mode from candidate blocks used for the merge mode of the current block; selecting one of the merge candidates to derive motion information of the current block based on the index information; deriving the motion information of the current block based on the selected merge candidate; deriving prediction samples on the current block based on the derived motion information; and generating reconstructed samples on the current block based on the prediction samples, wherein the candidate blocks used for the merge mode are searched in a region in which candidate blocks used for a mode using motion vector predictor, hereafter referred to as AMVP mode, are searched, wherein the merge mode is an inter prediction mode in which a motion vector of a candidate block for the merge mode is used as a motion vector of the current block, wherein the AMVP mode is an inter prediction mode in which a motion vector of a candidate block for the AMVP mode is used as the motion vector predictor for the current block, and wherein the candidate blocks used for the merge mode and for the AMVP mode include a first neighboring block located in a left side of the current block, a second neighboring block located in an upper side of the current block, a third neighboring block located at the bottom left corner of the current block, a fourth neighbor block located at the top right corner of the current block, and a fifth neighboring block located at the top left corner of the current block.