Down-up sampling of images is an essential process for spatial scalability of the video coding standard. We propose an efficient down-up sampling method in spatial domain using DCT kernel. The computational complexity of the proposed method is reduced by taking advantages of various symmetries of the combined DCT kernel. The proposed down-up sampling method is compared to that of MPEG-21 SVM 3.0 [1]. The proposed method outperforms the performance of MPEG-21 SVM 3.0 with slightly increased addition operation.