Provided are a method and an apparatus for coefficient scan on the base of a partition mode of a prediction unit. The method comprises the steps of: determining a scan method on the basis of a partition mode of a prediction unit; and encoding the information about the scan method, wherein the scan method is determined, on the basis of RDO (Rate Distortion optimization), from among the extracted candidate scan methods which have been extracted with consideration of the shapes of the partitions of the partition mode.