A decoding circuit, a decoding device, and a decoding system are included for decoding a B picture encoded by a direct mode at a high speed. A decoding process of an n-th macroblock is performed in parallel with transfer of a motion vector of an anchor block for an (n+1)-th macroblock to a buffer 106. With this construction, even if the (n+1)-th macroblock is encoded by the direct mode, a motion vector can be immediately calculated using the motion vector of the anchor block for the (n+1)-th macroblock in the buffer 106, when the (n+1)-th macroblock is decoded during a time T2.