An encoding apparatus includes: a memory; and a processor coupled to the memory and configured to: generate a value corresponding to a reference direction selected in intra prediction for a process target block by converting a value indicating the reference direction in accordance with a shape of the process target block; calculate a predicted value in the process target block from the values corresponding to the reference directions generated in intra prediction for neighboring blocks adjacent to the process target block; and generate a binary signal for arithmetic encoding based on the predicted value and the value corresponding to the reference direction generated in the intra prediction for the process target block.