This paper describes the development of the monocular autonomy following vehicle which for reduce a helper burden. The system is composed by a CCD camera, a FPGA board and some control circuits. Our idea is that the distance between the system and the target human is related to the size of the human region in the camera image. Based on this idea, we proposed the automatic human region detection method with S-ACM which is a kind of active contour model. We implemented our method and developed the system. The experiment which followed the target human was done. As the result, we confirmed that the system followed with keeping a fixed distance with the target human