An inter prediction method by a decoding apparatus, the method comprising: receiving video information including a skip flag, prediction mode information, partition information and a merge flag; checking the skip flag representing whether a skip mode is applied for a current coding unit; checking the prediction mode information and the partition information based on the skip flag representing that the skip mode is not applied for the current coding unit, wherein the prediction mode information represents whether an inter prediction is applied for the current coding unit, and the partition information represents a partition type for the current coding unit, wherein a prediction unit is derived from the current coding unit based on the partition type; checking the merge flag representing whether a merge mode is applied for a prediction unit, based on the skip flag representing that the skip mode is not applied for the current coding unit and a prediction mode representing that the inter prediction is applied for the current coding unit; and performing inter prediction on the prediction unit based on the merge flag representing whether merge mode is applied for the prediction unit, generating reconstructed block based on the result of the inter prediction, wherein the partition information and the prediction mode information are checked by the decoding apparatus between checking of the skip flag and checking of the merge flag by the decoding apparatus, wherein the partition information includes a binary code for the partition type used for the inter prediction of the current coding unit, wherein the partition type for the inter prediction is one of partition types comprising 2N×2N partition type, 2N×N partition type, and N×2N partition type, wherein a binary code for the 2N×2N partition type is '1', a binary code for the 2N×N partition type is '01', and a binary code for the N×2N partition type is '001'. receiving video information including a skip flag, prediction mode information, partition information and a merge flag; checking the skip flag representing whether a skip mode is applied for a current coding unit; checking the prediction mode information and the partition information based on the skip flag representing that the skip mode is not applied for the current coding unit, wherein the prediction mode information represents whether an inter prediction is applied for the current coding unit, and the partition information represents a partition type for the current coding unit, wherein a prediction unit is derived from the current coding unit based on the partition type; checking the merge flag representing whether a merge mode is applied for a prediction unit, based on the skip flag representing that the skip mode is not applied for the current coding unit and a prediction mode representing that the inter prediction is applied for the current coding unit; and performing inter prediction on the prediction unit based on the merge flag representing whether merge mode is applied for the prediction unit, generating reconstructed block based on the result of the inter prediction, wherein the partition information and the prediction mode information are checked by the decoding apparatus between checking of the skip flag and checking of the merge flag by the decoding apparatus, wherein the partition information includes a binary code for the partition type used for the inter prediction of the current coding unit, wherein the partition type for the inter prediction is one of partition types comprising 2N×2N partition type, 2N×N partition type, and N×2N partition type, wherein a binary code for the 2N×2N partition type is '1', a binary code for the 2N×N partition type is '01', and a binary code for the N×2N partition type is '001'.