We Claim:
1. An image decoding device comprising:
a variable length decoding unit (31) for performing variable-length decoding process on coded data multiplexed into a bitstream to obtain compressed data, coding mode and index information, each associated with a coding block;
a motion compensated prediction unit (54) for performing a motion compensation prediction process on said coding block based on said coding mode to generate a prediction image using a motion vector selected from one or more selectable motion vector candidate, said motion compensated prediction unit (54) selecting said motion vector indicated by said index information;
a decoded image generating unit (56) for generating decoded image data by adding a difference image which is obtained by decoding said compressed data and said prediction image generated by said motion compensated prediction unit (54);
characterized in that;
said motion compensated prediction unit (54) selects a spatial motion vector which is obtained from a decoded block located around said coding block or a temporal motion vector which is obtained from a decoded picture which can be referred to by said coding block according to said index information; and
said motion compensated prediction unit prepares a list of said motion vector candidates including one or more spatial motion vectors which is obtained from a decoded block located around said coding block and/or a temporal motion vector which is obtained from decoded pictures which can be referred to by said coding block, said motion vector candidates being listed in accordance with a predetermined order.
2. An image decoding method comprising:
a step for performing a variable-length decoding process on coded data multiplexed into a bitstream to obtain compressed data, coding mode and index information, each associated with a coding block;

a step for performing a motion compensation prediction process on said coding block based on said coding mode to generate a prediction image using a motion vector selected from one or more selectable motion vector candidate, said motion vector is selected according to said index information;
a step for generating decoded image data by adding a difference image which is obtained by decoding said compressed data and said prediction image; wherein
said motion vector candidate includes at least a spatial motion vector which is obtained from a decoded block located around said coding block or a temporal motion vector which is obtained from a decoded picture which can be referred to by said coding block and
said motion compensated prediction unit prepares a list of said motion vector candidates including one or more spatial motion vectors which is obtained from a decoded block located around said coding block and/or a temporal motion vector which is obtained from decoded pictures which can be referred to by said coding block, said motion vector candidates being listed in accordance with a predetermined order.