1. A moving picture decoding method, which generates a predicted image using information on motion vectors and information on reference images, the moving picture decoding method having multiple prediction modes including a mode without motion vector decoding, comprising: a step of selecting a frame(s) to be referenced to in the prediction of each prediction direction in the prediction mode from among multiple candidate reference frames, and a step of selecting motion vector information used in the prediction mode, wherein said step of selecting motion vector information is performed based on whether candidate blocks including the block adjacent to the left side of or the upper side of a current block have a motion vector; and moving picture decoding is performed by generating said predicted image using the information on said selected reference frame and the information on said selected motion vectors in said prediction mode.