A picture decoding method for decoding a coded moving picture, said method comprising: specifying (S210, S400) three neighboring blocks (B, C, D), the three neighboring blocks being located in a neighborhood of a current block and having been already decoded; judging (S202, S402) if each of the three neighboring blocks has been decoded using a motion vector of another block, and further judging if a reference picture referred to in decoding of the current block is the same as a reference picture referred to in decoding of each of the three neighboring blocks; deriving (S206, S208, S414) a predictive motion vector of the current block to be a median of the motion vectors of the three neighboring blocks when it is judged, in said judging, that more than one of the three neighboring blocks refers to the same reference picture as the current block; decoding a coded motion vector of the current block to obtain a decoded difference motion vector of the current block; recovering a motion vector of the current block by adding (S210, S416) the decoded difference motion vector of the current block and the predictive motion vector; generating a motion compensated picture using the recovered motion vector of the current block and a reference picture corresponding to the recovered motion vector of the current block; decoding a coded prediction error of the current block to obtain a decoded prediction error of the current block; and recovering the current block by adding the decoded prediction error and the motion compensated picture, characterized in that in the case where at least one of the three neighboring blocks is coded in a skip mode in which said one neighboring block is coded using the motion vector of said another block, the motion vector of said one neighboring block is calculated from the motion vector of said another block; and the predictive motion vector of the current block is derived in said deriving using the motion vector of said one neighboring block which is calculated from the motion vector of said another block. specifying (S210, S400) three neighboring blocks (B, C, D), the three neighboring blocks being located in a neighborhood of a current block and having been already decoded; judging (S202, S402) if each of the three neighboring blocks has been decoded using a motion vector of another block, and further judging if a reference picture referred to in decoding of the current block is the same as a reference picture referred to in decoding of each of the three neighboring blocks; deriving (S206, S208, S414) a predictive motion vector of the current block to be a median of the motion vectors of the three neighboring blocks when it is judged, in said judging, that more than one of the three neighboring blocks refers to the same reference picture as the current block; decoding a coded motion vector of the current block to obtain a decoded difference motion vector of the current block; recovering a motion vector of the current block by adding (S210, S416) the decoded difference motion vector of the current block and the predictive motion vector; generating a motion compensated picture using the recovered motion vector of the current block and a reference picture corresponding to the recovered motion vector of the current block; decoding a coded prediction error of the current block to obtain a decoded prediction error of the current block; and recovering the current block by adding the decoded prediction error and the motion compensated picture, characterized in that in the case where at least one of the three neighboring blocks is coded in a skip mode in which said one neighboring block is coded using the motion vector of said another block, the motion vector of said one neighboring block is calculated from the motion vector of said another block; and the predictive motion vector of the current block is derived in said deriving using the motion vector of said one neighboring block which is calculated from the motion vector of said another block.