PURPOSE: To constitute a small scale circuit by alternately storing moving vector data in two storage area parts in a post-buffer memory and reading out the moving vector data from one storage area part which is not being used for writing at present.

CONSTITUTION: The image movement detecting circuit is provided with the post-buffer memory 17 for alternately storing moving vector data outputted from respective arithmetic processing parts 9 to 12 in the C storage area part 18 and the D storage area part 19 in each unit processing area and reading out the moving vector data from the area part 18 or 19 which is not being used for writing at present synchronously with image data corresponding to a TV signal. Since the buffer memories 1, 17 are connected to the preposition and post-position of the arithmetic processing parts 9 to 12, each buffer memory is divided into area parts to be individually controlled for writing and reading and plural arithmetic processing parts 9 to 12 execute the parallel processing of the moving vectors of respective blocks, slow processing speed is allowable for respective arithmetic processing parts 9 to 12. Consequently, the small scale circuit constitution can be attained.