A picture coding method for coding a moving picture, said method comprising: specifying (S100, S300) three neighboring blocks (B, C, D), the three neighboring blocks being located in a neighborhood of a current block and having been already coded; judging (S102, S302) if each of the three neighboring blocks has been coded using a motion vector of another block, and further judging if a reference picture referred to in coding of the current block is the same as a reference picture referred to in coding of each of the three neighboring blocks; deriving (S106, S108, S314) 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; coding (S110, S316) a difference value between a motion vector of the current block and the predictive motion vector derived by said deriving; generating a motion compensated picture using the motion vector of the current block and a reference picture corresponding to the motion vector of the current block; and coding a prediction error between the current block and the motion compensated picture, characterized in that in the case where at least one of the three neighboring blocks has been 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 (S100, S300) three neighboring blocks (B, C, D), the three neighboring blocks being located in a neighborhood of a current block and having been already coded; judging (S102, S302) if each of the three neighboring blocks has been coded using a motion vector of another block, and further judging if a reference picture referred to in coding of the current block is the same as a reference picture referred to in coding of each of the three neighboring blocks; deriving (S106, S108, S314) 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; coding (S110, S316) a difference value between a motion vector of the current block and the predictive motion vector derived by said deriving; generating a motion compensated picture using the motion vector of the current block and a reference picture corresponding to the motion vector of the current block; and coding a prediction error between the current block and the motion compensated picture, characterized in that in the case where at least one of the three neighboring blocks has been 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.