Provided is a video decoding method including determining whether a random access point (RAP) picture is positioned in an enhancement layer; determining whether a random access skipped leading (RASL) picture related to the RAP picture is output; and if the RAP picture is positioned in the enhancement layer and the RASL picture is determined not to be output, activating a SPS corresponding to the RAP picture when the RAP picture that is not at a start point of a CVS is decoded.