Disclosed are a method and apparatus for encoding/decoding images. The image-decoding method comprises the steps of: receiving a bit stream including information regarding an NAL unit type; and checking whether or not the NAL unit in the bit stream is a reference picture based on said information regarding an NAL unit type and decoding the NAL unit. The information regarding an NAL unit type indicates whether the NAL unit is a reference reading picture or not a reference reading picture.