A video encoding apparatus includes an inter predictor to check for whether predetermined candidate adding conditions are satisfied, add into a merge candidate set including merge candidates corresponding to neighboring blocks of a current block, a combined bi-predictive motion parameter, the combined bi-predictive motion parameter generated by combining a list 0 motion parameter of a first available candidate block and a list 1 motion parameter of a second available candidate block, when the predetermined candidate adding conditions are satisfied, and predict the current block by using a motion parameter corresponding to a merge candidate selected from the merge candidate set, to thereby generate a predicted block for the current block. Herein, the merge candidate set corresponds to a maximum number of the merge candidates, the maximum number of the merge candidates corresponding to information on the number of the merge candidates included in a bistream.