An apparatus for decoding a motion vector of a current block of an image from a bitstream comprising encoded video, the apparatus comprising: a predictor which, when a prediction mode information of the current block is inter-prediction and a motion vector predictor of the current block is determined based on a motion vector predictor information indicating the motion vector predictor of the current prediction unit, is configured to receive the motion vector predictor information, determine motion vector predictor candidates by using motion vectors of previously decoded blocks adjacent to the current block, and determine the motion vector predictor of the current block which is one motion vector selected from among motion vector predictor candidates based on the motion vector predictor information, the motion vector predictor information being obtained from the bitstream; and a motion vector restoring unit which is configured to obtain a motion vector of the current block based on the motion vector predictor and a differential vector obtained from the bitstream, wherein the previously decoded blocks comprise a first block located on a lower-left side of the current block, that is, directly below a lower-most block among left blocks adjacent to a left side of the current block and located outside the current block and a second block is located on an upper side of the first block, wherein the image is split into a plurality of square maximum coding units, according to information about a maximum size of a coding unit, and each of the plurality of maximum coding units are independently split into square coding units of coded depths according to depths by equally dividing both height and width of the maximum coding unit by two, wherein a coding unit of a current depth is one of square data units split from a coding unit of an upper depth, wherein the coding unit of the current depth is split into square coding units of a lower depth, independently from neighboring coding units, by equally dividing both height and width of the coding unit of the current depth by two and wherein each of the coding units comprises one or more prediction units for prediction decoding, whereby the one or more prediction units are obtained by equally splitting a width or a height of a current coding unit by two, or by equally splitting both the height and the width of the current coding unit by two, or by determining the current coding unit as the one prediction unit and wherein each of the coding units comprises one or more transformation units for inverse transformation, whereby the one or more transformation units are obtained by equally dividing both the height and width of the current coding unit or by determining the current coding unit as the one transformation unit, and wherein the current block is a prediction unit obtained from one of the coding units. a predictor which, when a prediction mode information of the current block is inter-prediction and a motion vector predictor of the current block is determined based on a motion vector predictor information indicating the motion vector predictor of the current prediction unit, is configured to receive the motion vector predictor information, determine motion vector predictor candidates by using motion vectors of previously decoded blocks adjacent to the current block, and determine the motion vector predictor of the current block which is one motion vector selected from among motion vector predictor candidates based on the motion vector predictor information, the motion vector predictor information being obtained from the bitstream; and a motion vector restoring unit which is configured to obtain a motion vector of the current block based on the motion vector predictor and a differential vector obtained from the bitstream, wherein the previously decoded blocks comprise a first block located on a lower-left side of the current block, that is, directly below a lower-most block among left blocks adjacent to a left side of the current block and located outside the current block and a second block is located on an upper side of the first block, wherein the image is split into a plurality of square maximum coding units, according to information about a maximum size of a coding unit, and each of the plurality of maximum coding units are independently split into square coding units of coded depths according to depths by equally dividing both height and width of the maximum coding unit by two, wherein a coding unit of a current depth is one of square data units split from a coding unit of an upper depth, wherein the coding unit of the current depth is split into square coding units of a lower depth, independently from neighboring coding units, by equally dividing both height and width of the coding unit of the current depth by two and wherein each of the coding units comprises one or more prediction units for prediction decoding, whereby the one or more prediction units are obtained by equally splitting a width or a height of a current coding unit by two, or by equally splitting both the height and the width of the current coding unit by two, or by determining the current coding unit as the one prediction unit and wherein each of the coding units comprises one or more transformation units for inverse transformation, whereby the one or more transformation units are obtained by equally dividing both the height and width of the current coding unit or by determining the current coding unit as the one transformation unit, and wherein the current block is a prediction unit obtained from one of the coding units.