Provided is a scalable video coding method and apparatus. Motion data of a high-quality fine grain scalability (FGS) layer is used for interlayer coding in order to remove redundancy between coarse grain scalability (CGS) layers or layers having different spatial resolutions, and information indicating that data of the FGS layer has been used for interlayer motion prediction is inserted for Moving Picture Expert Group (MPEG)-4 scalable video encoding. A bitstream extractor checks the information and performs extraction to maintain the data of the FGS layer. MPEG-4 scalable video decoding is performed using the information. By using the FGS layer, interlayer redundancy can be efficiently removed, thereby improving encoding efficiency.