An image decoding method performed by a decoding apparatus, the method comprising: configuring an advanced motion vector prediction, AMVP, candidate list including at least one AMVP candidate for a current block; deriving a history-based motion vector prediction, HMVP, buffer for the current block, the HMVP buffer including HMVP candidates for the current block; deriving an updated AMVP candidate list by adding at least one additional candidate, wherein the at least one additional candidate is derived by using the at least one HMVP candidate selected from among the HMVP candidates in the HMVP buffer; deriving motion information for the current block based on the updated AMVP candidate list; deriving prediction samples for the current block based on the motion information for the current block; and generating reconstructed samples for the current block based on the prediction samples for the current block, wherein the at least one HMVP candidate is selected from among the HMVP candidates based on an HMVP buffer index, wherein a value of the HMVP buffer index respectively represents the at least one HMVP candidate among the HMVP candidates, characterized in that an HMVP candidate added to the HMVP buffer priorly has a relatively lower HMVP buffer index, wherein for deriving the updated AMVP candidate list, a first HMVP candidate of the HMVP candidates is selected before a second HMVP candidate of the HMVP candidates, wherein the first HMVP candidate is represented by a relatively lower HMVP buffer index and the second HMVP candidate is represented by a relatively higher HMVP buffer index, and wherein a pruning process by using the at least one AMVP candidate is not applied to each of the at least one HMVP candidate. configuring an advanced motion vector prediction, AMVP, candidate list including at least one AMVP candidate for a current block; deriving a history-based motion vector prediction, HMVP, buffer for the current block, the HMVP buffer including HMVP candidates for the current block; deriving an updated AMVP candidate list by adding at least one additional candidate, wherein the at least one additional candidate is derived by using the at least one HMVP candidate selected from among the HMVP candidates in the HMVP buffer; deriving motion information for the current block based on the updated AMVP candidate list; deriving prediction samples for the current block based on the motion information for the current block; and generating reconstructed samples for the current block based on the prediction samples for the current block, wherein the at least one HMVP candidate is selected from among the HMVP candidates based on an HMVP buffer index, wherein a value of the HMVP buffer index respectively represents the at least one HMVP candidate among the HMVP candidates, characterized in that an HMVP candidate added to the HMVP buffer priorly has a relatively lower HMVP buffer index, wherein for deriving the updated AMVP candidate list, a first HMVP candidate of the HMVP candidates is selected before a second HMVP candidate of the HMVP candidates, wherein the first HMVP candidate is represented by a relatively lower HMVP buffer index and the second HMVP candidate is represented by a relatively higher HMVP buffer index, and wherein a pruning process by using the at least one AMVP candidate is not applied to each of the at least one HMVP candidate.