Method and apparatus for encoding/decoding image hierarchically

A method for hierarchically encoding/decoding an image and an apparatus thereof are provided to enable a terminal in which an existing codec is mounted and a terminal in which a new codec is mounted to reproduce a single stream together. A method for hierarchically encoding/decoding an image comprises the following steps of: generating a basic image by down-sampling an original image(1001); generating a basic layer bit stream by encoding the basic image; generating the restored image of the basic image(1006); up-sampling the restored image(1007); and generating expanded layer bit streams by encoding the residual image between the original image and the up-sampled image by using different quantization parameters(1010).