An electronic device for motion compensation is provided. The electronic device has a processing unit configured to perform a decoding program on a video bitstream to output decoding data, wherein the decoding data has a plurality of inter-prediction macroblocks, and the processing unit further generates a plurality of first pixel interpolation values according to the inter-prediction macroblocks which are smaller than a predetermined macroblock size. A motion compensation acceleration circuit is configured to generate a plurality of second pixel interpolation values according to the inter-prediction macroblocks which are larger than or equal to the predetermined macroblocks size, and generate a plurality of reconstructed macroblocks according to the first pixel interpolation values, the second pixel interpolation values, and a plurality of corresponding residue values.