PURPOSE: To detect a motion vector accurately even when a fluctuation of a DC component is in existence in a picture by the motion vector detection circuit used for picture compression or the like.

CONSTITUTION: The circuit is provided with a high pass filter 11 eliminating a DC level of a picture signal. Then the output is given to a U' block extract circuit 12 and a frame memory 2 to move picture elements of the frame latched in the frame memory 2. Then the U block and a Us' block moved thereto are extracted. Then moving quantity is sequentially changed to detect an absolute value of each difference thereby detecting a motion vector. Thus, even when the DC component is fluctuated, the motion vector is detected accurately.