A spatial error concealment (SEC) method for concealing a spatial image error of an encoded image frame caused by a damaged macroblock (MB) is provided. The SEC method selects a proper SEC algorithm by adaptively classifying a plurality of correct MBs adjacent to the damaged MB, so as to execute interpolation pixel compensation or matching block copying, thus obtaining image data of the damaged MB. In such a way, the damaged MB is processed to apply the least affection to the entire image frame. The SEC algorithm is selected from bilinear interpolation (BI) method, directional interpolation (DI) method, multi-directional interpolation (MDI) method, and best neighborhood matching (BNM) method. The SEC method further includes a fast determination calculation, which utilizes image directional data related to the damaged MB in coding data of the original frame to execute a direct SEC process, for saving time on determination calculation, thus accelerating the processing speed.