A method of constructing a merge candidate list for video coding, comprising: constructing a merge candidate list using available spatial and temporal merge candidates, and deriving motion information using a merge index and the merge candidate list; generating a prediction block using the motion information; generating a quantization block by inverse-scanning quantized coefficient components according to a diagonal scan, inverse-quantizing the quantization block using a quantization parameter and a quantization matrix, and inverse transform the inversely-quantized quantization block to generate a residual block; deriving a reconstructed block using the prediction block and the residual block, wherein the spatial merge candidates are motion information of spatial merge candidate blocks, and the spatial merge candidate blocks are a left block, an above block, an above-right block, a left-below block or an above-left block of the current block, wherein the spatial merge candidate corresponding to a first prediction unit partitioned by asymmetric partitioning is set as unavailable if a current prediction unit is a second prediction unit partitioned by the asymmetric partitioning, and wherein the quantization parameter is generated using a differential quantization parameter and a quantization parameter predictor, wherein the quantization parameter predictor is generated using an average of a left quantization parameter and a above quantization parameter when both of the left quantization parameter and the above quantization parameter are available, and wherein, when only one of the left quantization parameter and the above quantization parameter is available, the quantization parameter is generated using an average of the available quantization parameter and a previous quantization parameter. constructing a merge candidate list using available spatial and temporal merge candidates, and deriving motion information using a merge index and the merge candidate list; generating a prediction block using the motion information; generating a quantization block by inverse-scanning quantized coefficient components according to a diagonal scan, inverse-quantizing the quantization block using a quantization parameter and a quantization matrix, and inverse transform the inversely-quantized quantization block to generate a residual block; deriving a reconstructed block using the prediction block and the residual block, wherein the spatial merge candidates are motion information of spatial merge candidate blocks, and the spatial merge candidate blocks are a left block, an above block, an above-right block, a left-below block or an above-left block of the current block, wherein the spatial merge candidate corresponding to a first prediction unit partitioned by asymmetric partitioning is set as unavailable if a current prediction unit is a second prediction unit partitioned by the asymmetric partitioning, and wherein the quantization parameter is generated using a differential quantization parameter and a quantization parameter predictor, wherein the quantization parameter predictor is generated using an average of a left quantization parameter and a above quantization parameter when both of the left quantization parameter and the above quantization parameter are available, and wherein, when only one of the left quantization parameter and the above quantization parameter is available, the quantization parameter is generated using an average of the available quantization parameter and a previous quantization parameter.