A method for an image reducing processing circuit includes the memory architecture of two FIFO units. The method includes the following steps of: providing an input processing unit receiving original image data and delivering the image data; providing a horizontal direction image processing unit receiving the image data from the input processing unit; providing a first step FIFO unit receiving the image data from the horizontal direction image processing unit to read and write the image data on the same access frequency; providing a vertical direction image processing unit receiving the image data from the first step FIFO unit; providing a second step FIFO unit receiving the image data from the vertical direction image processing unit and implementing the readout/writing of the image data on two access frequency, and providing an output processing unit receiving the image data from the second step FIFO unit and outputting reduced image.