The image decoding method and image decoding apparatus

An image encoding method includes steps of: storing an encoded picture identified by a picture number as a reference picture in a storage section; generating a command for corresponding coefficient used for generating a prediction image and the reference index specifying a reference picture to the picture number; specifying a reference picture for performing motion compensation for the block on the picture to be encoded, by the reference index; generating a prediction image by performing a linear prediction using the coefficient corresponding to the reference index for the block obtained by the motion detection in the reference picture specified; and outputting an image encoding signal containing an encoding signal where a prediction residue as a difference between the block in the picture input to be encoded and the prediction image, the command, the reference index, and the coefficient are encoded; wherein information indicating the maximum value of the reference index is encoded in the image encoding signal and a command for relating a plurality of reference indexes to one or more picture numbers is generated.