An image encoding method for encoding blocks of pictures by means of inter prediction based on reference pictures including short-term reference pictures and long-term reference pictures, the image encoding method comprising: deriving a candidate for a motion vector predictor to be used in encoding of a motion vector for a current block to be encoded, from a first motion vector for a neighboring block which is included in a current picture including the current block and is adjacent to the current block; adding the derived candidate to a list of candidates; selecting one motion vector predictor from the list of candidates; and encoding the current block using the motion vector for the current block and a reference picture for the current block, and encoding the motion vector for the current block using the selected motion vector predictor; wherein, when the reference picture for the current block is a short-term reference picture, the deriving includes: determining whether a first reference picture for the neighboring block is a long-term reference picture or a short-term reference picture, wherein the candidate is derived from the first motion vector only when the first reference picture for the neighboring block is determined to be a short-term reference picture, and scaling the first motion vector by using a ratio of a first temporal distance between the reference picture for the current block and the current picture and a second temporal distance between the first reference picture for the neighboring block and the current picture, and deriving the scaled first motion vector as the candidate, when the first reference picture for the neighboring block is determined to be a short-term reference picture; wherein, when the reference picture for the current block is a long-term reference picture, the first motion vector is derived as the candidate. deriving a candidate for a motion vector predictor to be used in encoding of a motion vector for a current block to be encoded, from a first motion vector for a neighboring block which is included in a current picture including the current block and is adjacent to the current block; adding the derived candidate to a list of candidates; selecting one motion vector predictor from the list of candidates; and encoding the current block using the motion vector for the current block and a reference picture for the current block, and encoding the motion vector for the current block using the selected motion vector predictor; wherein, when the reference picture for the current block is a short-term reference picture, the deriving includes: determining whether a first reference picture for the neighboring block is a long-term reference picture or a short-term reference picture, wherein the candidate is derived from the first motion vector only when the first reference picture for the neighboring block is determined to be a short-term reference picture, and scaling the first motion vector by using a ratio of a first temporal distance between the reference picture for the current block and the current picture and a second temporal distance between the first reference picture for the neighboring block and the current picture, and deriving the scaled first motion vector as the candidate, when the first reference picture for the neighboring block is determined to be a short-term reference picture; determining whether a first reference picture for the neighboring block is a long-term reference picture or a short-term reference picture, wherein the candidate is derived from the first motion vector only when the first reference picture for the neighboring block is determined to be a short-term reference picture, and scaling the first motion vector by using a ratio of a first temporal distance between the reference picture for the current block and the current picture and a second temporal distance between the first reference picture for the neighboring block and the current picture, and deriving the scaled first motion vector as the candidate, when the first reference picture for the neighboring block is determined to be a short-term reference picture; wherein, when the reference picture for the current block is a long-term reference picture, the first motion vector is derived as the candidate.