A decoding method for decoding a control parameter for controlling the decoding of an image, the decoding method comprising: determining a context for the control parameter of a current block in the image, from among a plurality of contexts, according to a signal type of the control parameter; and performing arithmetic decoding on a bitstream corresponding to the current block to obtain the control parameter for the current block by using the determined context; wherein the determining includes: determining the context for a split flag by using both hierarchical depths for the left and the upper block of the current block; determining the context for a skip flag by using both of the decoded skip flags for the left and the upper block; and determining a predetermined fixed context for a merge flag without using any of the decoded merge flags for the left block and the upper block; wherein the split flag indicates whether or not the current block is partitioned into a plurality of blocks; the skip flag indicates whether or not the current block is a skipped block; and the merge flag indicates whether or not a merge mode is used for the current block; wherein the merge mode is a mode in which a motion vector and a reference picture index are copied from a neighboring block of the current block. determining a context for the control parameter of a current block in the image, from among a plurality of contexts, according to a signal type of the control parameter; and performing arithmetic decoding on a bitstream corresponding to the current block to obtain the control parameter for the current block by using the determined context; wherein the determining includes: determining the context for a split flag by using both hierarchical depths for the left and the upper block of the current block; determining the context for a skip flag by using both of the decoded skip flags for the left and the upper block; and determining a predetermined fixed context for a merge flag without using any of the decoded merge flags for the left block and the upper block; wherein the split flag indicates whether or not the current block is partitioned into a plurality of blocks; the skip flag indicates whether or not the current block is a skipped block; and the merge flag indicates whether or not a merge mode is used for the current block; wherein the merge mode is a mode in which a motion vector and a reference picture index are copied from a neighboring block of the current block. determining the context for a split flag by using both hierarchical depths for the left and the upper block of the current block; determining the context for a skip flag by using both of the decoded skip flags for the left and the upper block; and determining a predetermined fixed context for a merge flag without using any of the decoded merge flags for the left block and the upper block; wherein the split flag indicates whether or not the current block is partitioned into a plurality of blocks; the skip flag indicates whether or not the current block is a skipped block; and the merge flag indicates whether or not a merge mode is used for the current block; wherein the merge mode is a mode in which a motion vector and a reference picture index are copied from a neighboring block of the current block.