Provided is a video decoding method performed by a video decoding apparatus, the video decoding method including: determining prediction mode information of a current block and an index indicating a prediction candidate, from a bitstream; determining a prediction candidate list according to the prediction mode information; when the prediction mode information of the current block indicates a pre-set prediction mode, determining a motion vector indicated by the index indicating the prediction candidate from the prediction candidate list, and determining a prediction motion vector of the current block based on at least one of pieces of motion prediction information related to the motion vector; and determining a motion vector of the current block based on the prediction motion vector, wherein the pre-set prediction mode is a prediction mode different from a skip mode and a merge mode.