An image decoding method for generating an image by decoding a coded bitstream, the image decoding method characterized by comprising: obtaining buffer descriptions (BD0 - BDn) from a sequence parameter set included in the coded bitstream, each of the buffer descriptions (BD0 - BDn) includes buffer elements (BEO - BE2), wherein each of the buffer elements (BEO -BE2) (i) is associated with a buffer element index and (ii) specifies a reference picture to be held in a buffer for decoding pictures; constructing a default reference picture list including all the reference pictures that are indicated in the buffer descriptions (BD0 - BDn) according to a predetermined constructing scheme; obtaining, from a slice header of a current slice included in the coded bitstream, buffer description selecting information for specifying one of the buffer descriptions (BD0 - BDn); selecting the buffer description (BD0 - BDn) specified in the buffer description selecting information; obtaining buffer description updating information from the slice header, wherein the buffer description updating information includes a buffer element index of a buffer element (BEO - BE2) included in the selected buffer description (BD0 - BDn) and a POC difference between a reference picture to be associated with the buffer element and the current slice; modifying the buffer element (BEO - BE2) included in the selected buffer description (BDO - BDn) and indicated in the buffer description updating information; obtaining reference list reordering information from the slice header, wherein, in the reordering information, a target reference picture to be reordered is specified by a buffer element index in the selected and modified buffer description; reordering reference pictures included in the default reference picture list which corresponds to the selected and modified buffer description to define a first reference picture list, based on the reference list reordering information; reordering reference pictures included in the default reference picture list which corresponds to the selected and modified buffer description to define a second reference picture list, based on the reference list reordering information; and decoding the current slice using the selected and modified buffer description (BDO - BDn), the first reference picture list and the second reference picture list. obtaining buffer descriptions (BD0 - BDn) from a sequence parameter set included in the coded bitstream, each of the buffer descriptions (BD0 - BDn) includes buffer elements (BEO - BE2), wherein each of the buffer elements (BEO -BE2) (i) is associated with a buffer element index and (ii) specifies a reference picture to be held in a buffer for decoding pictures; constructing a default reference picture list including all the reference pictures that are indicated in the buffer descriptions (BD0 - BDn) according to a predetermined constructing scheme; obtaining, from a slice header of a current slice included in the coded bitstream, buffer description selecting information for specifying one of the buffer descriptions (BD0 - BDn); selecting the buffer description (BD0 - BDn) specified in the buffer description selecting information; obtaining buffer description updating information from the slice header, wherein the buffer description updating information includes a buffer element index of a buffer element (BEO - BE2) included in the selected buffer description (BD0 - BDn) and a POC difference between a reference picture to be associated with the buffer element and the current slice; modifying the buffer element (BEO - BE2) included in the selected buffer description (BDO - BDn) and indicated in the buffer description updating information; obtaining reference list reordering information from the slice header, wherein, in the reordering information, a target reference picture to be reordered is specified by a buffer element index in the selected and modified buffer description; reordering reference pictures included in the default reference picture list which corresponds to the selected and modified buffer description to define a first reference picture list, based on the reference list reordering information; reordering reference pictures included in the default reference picture list which corresponds to the selected and modified buffer description to define a second reference picture list, based on the reference list reordering information; and decoding the current slice using the selected and modified buffer description (BDO - BDn), the first reference picture list and the second reference picture list.