A coding apparatus for hierarchically (layering) coding top field data and bottom field data divided from each of a plurality of picture data composing a moving picture image has a first coding unit configured to encode one field data between two field data of the top field data and the bottom field data divided from the picture data, a conversion unit configured to interpolate first predicted image data generated by the first coding unit encoding above one field data and generate a second predicted image data of a scanning position of the other field data between the two field data, and a second coding unit configured to encode the other field data between the two field data based on the second predicted image data generated by the conversion unit.